THE DANISH INGOLF- EXPEDITION.

VOLUME II.

2.

ON THE APPENDICES GENITALES IN THE

GREENLAND SHARK, SOMNIOSUS MICROCEPHALUS

(RL. SCHN.), AND OTHER SELACHIANS.

BY

HECTOR F. E. JUNGERSEN.

WITH 6 PLATES AND 2S FIGURES IN THE TEXT.

TRANSLATED BY TORBEN LUNDBECK.

->4*:x*<-

COPENHAGEN.

BIANCO LUNO (F. DREYER), PRINTER TO THE COURT.

1899.

CONTENTS.

On the Appendices Qenitales in the Greenland Shark, Somniosus Microcephalia (Bl. Schn.)> and other Selachians.

Page

Introductory remarks I.

I. The appendages of the Ventrals in the Greenland

Shark I,

II. The ventral appendages in other Selachians 17

1. A general view of the Copulatory appendages in
the Selachians 17

2. Special part 27

Selachoidei 27

Spinacidae: Acanthias vulgaris Risso 27

Spinax niger Bonap 29

Scyumus lichia Bonap 31

Scylliidse: ScyUiutn canicula (L.) 32

— Scyllium stellare (L.) 34

— Pristiurus melanostomus (Bonap.) ... 36
Lamnidae: Lamna cornubica (Gmelin) 37

Selachus maximus (Gunnerus) 39

Rhinidae: Rhina squatina (L.) 41

Cestraciontidae : Heterodontus (Cestracion) Phillipi

(Cuv.) 45

Notidanidae: Chlamydoselachus anguineus Garman 45

Page

Carchariidae: Mustelus antarcticus Gthr 46.

Batoidei 47

Torpedinidae : Torpedo marniorata Risso 47

— Torpedo oculata Belon 50

Narcine sp 50.

Rhinobatidae : Rhinobatus columns: Bonap 52

Trygonidae: Trygon violacea Bonap 53

Rajidae 55

— Raja batds L 56

— Raja nidarosiensis Collett 59,

Raja clavata L 59

— Raja radiata Donovan 63

— Raja fyllas Ltk 66.

— Raja circularis Couch 67

Holocephala 6S

Chimaera monstrosa L 69

Callorhynchus antarcticus (Lacep.) 74.

3. Which is the function of the appendices genitales? 77

Addenda S2

Explanation of the Plates S4

419-.'

On the Appendices Genitales (CJaspers)

in the Greenland Shark, Somniosus microcephalus

(Bl. Schn.), and other Selachians.

By

Hector F. E. Jungersen.

The following treatise has its origin from the circumstance that during the stay at Iceland of the
cruiser Ingolf I endeavoured to gather informations as to several facts concerning the Green-
land Shark, not vet elucidated. I succeeded only in throwing light upon a single one of these obscure
facts bv gathering a suitable material. At the subsequent examination of this material I soon perceived
that the appendices genitales or claspers of the Selachians generally had hitherto been very imperfectly
examined although these organs on account of their conspicuous - - sometimes almost colossal -
dimensions have from time immemorial been known as characteristic for the males of cartilaginous
fishes. Of their functions only little is known with certainty, and on this- point I am not able to bring
new facts of any importance; but though the function must be supposed to be the same in all Sela-
chians, a rich variation is found in their structure, especially in the skeleton, the structure being
different from genus to genus or even from species to species. That, however, through all this
variation a common type may be shown to exist, also with respect to the skeleton and the muscles,
has not hitherto been seen, but will, I hope, with sufficient clearness be shown by the following trea-
tise. As a consequence of the way, in which the work has come into existence, I have divided it
into two parts, of which one deals with the Greenland Shark only, while the other treats of other
Plagiostomes and Holocephales.

I.

The Appendages of the Ventrals in the Greenland Shark.

The words with which Gunnerus 1 ) commences his treatise of the Greenland Shark: This fish
of the Haaekiud deserves to be somewhat better known to the learned than hitherto it has been
may be said to some extent to be in force to this day, our knowledge of this species of sharks being
still rather defective, although it is not only very frequently found in the northern seas, but is also
in several places the object of a large and regular fishery, as in our northern dependencies, espe-
cially off the coast of Iceland. It is so far less extraordinary, that many things with regard to

') Om Haa-Skierdingen. Det Throndhiemske Selskabs Skrifter. 2, 1763, p. 330.

The Tngolf-Expedilion. II. 2. !

ON THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK.

its biological conditions are unknown, as the same thing may be said of many common species of
fishes on onr own coasts ; but it seems more remarkable that we do not even know for certain whether
the Greenland Shark is viviparous or oviparous, and that several features of the anatomical structure
of the animal are unknown or only deficiently known. Although this species of Sharks is rather
frequently found on the more populated European coasts — also on ours -- and more than once has
come into the hands of naturalists, even anatomists, we are thus far from being perfectly acquainted
with the structure of its urinary and reproductive organs.

The facts which have in later years been brought forth as to the latter — and upon the whole
concerning the «viscera» of the Greenland Shark -- are due to Sir William Turner, who has exa-
mined several specimens from British coasts and has given his results in The Journal of Anatomy and
Physiology : ).

As to the female the first of these communications (i) showed the surprising result that
oviducts were wanting. Consequently the Greenland Shark would necessarily be oviparous, and the
ova, detached from the ovary, would presumably leave the abdominal cavity through the abdominal
pores to be impregnated outside the mother. That the ovaries were immature in both the examined
animals of a respective length of n ft. 8 inches and 8 I / 2 ft. is however evident from the description.
Later (3) the first statement is corrected: oviducts 2 ) are found, opening as usual in the Sharks witli wide,
funnelshaped, closely united mouths before the liver, and running along the lower side of the kidneys
to the cloaca; in the examined specimen of 7 feet length they were about as thick as a goosequill;
the ovaries were quite immature. Still later (4) these parts are described in a somewhat more deve-
loped state in a Greenland Shark n ft. 6 in. long; the diameter of the oviduct was only 3/8 inch
(about 1 ctm.); the ovaries were quite immature. In none of these communications is shown, whether
any shell gland , any indication of an uterus, indications of folds of the mucous membrane or the
like were found. To judge from the fact of these structures not being mentioned, that nothing of
the kind is found, I do not think justifiable; a shell- gland for inst. is generally always found in
Sharks, whether they be oviparous or viviparous; more probably these structures on account of the
immature state of the animals have not been prominent, and therefore have not been noticed. For that
all the females examined by Sir W. Turner have been immature and young animals admits, I think,
of no doubt. The fact is that we know to a certainty that the mature ovarial eggs are about as large
as goose-eggs, but the largest mentioned by Sir W. Turner were only of the size of shot or at most
of small bullets, and we know that the Greenland Shark grows to a still more considerable size than
11 ft. 8 in.; therefore if the oviducts showed so small a size and besides (presumably) so simple a
shape, it is only, what might be expected in younger individuals 3) , and I see no reason at all to

A Contribution to the Visceral Anatomy of the Greenland Shark iLtemargus borealis). L. c. 7. 1S73, p. 233.
21 Additional observations on the Anatomy of the Greenl. Shark. L. c. 3, 1874, p. 285. 3) Note on the Oviducts of the Greenl.
Shark. I,, c. 12, 1878, p. 604. 4) Additional Note on the Oviducts etc. L. c. 19, 1S85, p. 221.

-• The oviducts had already been seen in 1S47 by Kneeland I Boston Journ. Nat. Hist. 5, p. 479, 485) in a specimen
of the length of 7 ft. 5 in.; the ovaries were immature. The first statement by Sir W.Turner has been repeated by
Furbringer: Zur vergl. Anat. u. Entwickelungsgesch. der Excretiousorgane der Vertebrateu iMorphol. Jahrb. 4, 1878] p. 53, 83;
it is found as late as in Guido Schneider: Ueber die Entw. der Genitalcanale bei Col/itis ttznia h- und Phoxinus Imvis
Ag. 1. Mem. Ac. Imp. d. Sc. de St. Petersbourg |8J T. 2, 1S951 p. 9.

i) Comp. J oh. Mfiller: Untersuchungen fiber die Eingeweide der Fische, Schluss der vergleichende Anatomie der
Myxinoiden (Abhdl. K. Ac. Wiss. Berlin 1843 [1845]], p. 133, 134.

ON THE APPENDICES GENITAI.ES (CLASPERS) IN THE GREENLAND SHARK.

suppose, as Sir W. Turner 1 ) does, another mode of bringing forth the ova in this than in other
Sharks; the ova certainly all get into the oviduct, and are impregnated there; whether they later are
laid or develop into embryos in the u terns must for the present be left undecided 2 ).

On the internal reproductive organs of the male only one communication (2) has been given,
concerning a specimen of the length of 6 ft. i in. The testes were immature; neither by the direct
examination of them and their mesorchium nor by injection from the renal duct was Sir W.Turner
able to detect any duct for the sperm, and from that he infers that distinct sexual ducts are also
wanting in the male, and that the sperm is evacuated into the abdominal cavity, thus cpiite corre-
sponding to the case of the females, as it the previous year had been understood with regard to those;
but while the statement has been corrected by T. himself with regard to the latter, nothing has as
vet come to light concerning the male. I think, however, that the supposition is allowable, that T.'s
inference is premature also with regard to the male; it is likely that vasa efferentia in this young,
immature specimen (which T. himself declares to be of immature growth ) were either not formed
at all or at all events not in a directly visible way 3). It must appear quite natural that also the
external male genitals were quite undeveloped in this specimen; the copulatory appendages were
only of a length of 1 3/8 inch, and were far from reaching the end of the fin-membrane (see the fig. 1. c.
p. 287). But these copulatory appendages seem always to have shown a q trite similar undeve-

*) Sir W.Turner evidently lias not been able quite to dismiss his original conception of the evacuation of the ova
through the abdominal pores (to which for the rest every parallel would be wanting, as the Cyclostomes have no abdominal
pores) ; even in his latest communication (4, 18S5 p. 222) T. says: < But, as it is very doubtful if the entire surface of each ovary
could be embraced by the spathe-like canal (i. e. the mouth of the oviduct), a proportion of the ova would probably be shed
into the peritoneal cavity, and be evacuated through the abdominal pores .

-1 Professor Ltitken in: Smaa Bidrag til Selachiernes Naturhistorie. 2. Om Havkalens Forplantning (Vid. Medd.
Naturh. Eoren. i Kbhvn. 1S79— So; p. 56) has tried to make it probable that the Greenland Shark should be oviparous, and
moreover have soft, shell-less eggs, which is known in no other plagiostome. Among the reasons that might give some
countenance to this notion Sir W. Turn er' s anatomical results are quoted. It is quite evident that if T.'s first communication
of the want of oviducts had been correct, a deposition of the eggs, and an impregnation of them outside of the body of the
female would have been as good as proved; but the later informations from the same author are in my opinion of such a
nature, that thev can be used as proofs neither for nor against a deposition of the eggs, but might — connected with my
demonstration in the following, that the male Greenland Shark has fully developed copulatory organs — be used as proofs
of the eggs, as generally in Sharks, being impregnated in the oviduct. The other reasons for a deposition of the eggs, quoted
by Professor L-, viz. the negative one that we have never hitherto got any foetus of the Greenland Shark, and the more posi-
tive accounts from several laymen of numerous large eggs, but always in the females, cannot, I think, prove anything either
in one or the other direction. Against the first of these reasons may be quoted the equally negative circumstance that we
have never found eggs of the Greenland Shark outside the animal neither, and against the second that the large eggs are
evidently ovarial eggs still coherent by the thin, distended ovarial stroma; for all informations — also those I have got
persouallv from an Icelandic Shark-fisher — state that the large eggs, which are only seen by the flensing, always cohere by
thin membranes or the like; but large and soft ovarial eggs, as is well known, are not only found in oviparous, but as well
in viviparous Sharks and Ravs. As however the only earlier authors, who state anything at all about the propagation, declare
quite positively, that the Greenland Shark is viviparous, viz. besides Otto Fabricius and Faber, who are both cited by
Professor Eiitken, also David Cranz, who says in his Historie vou Gronland . 2. Anil. 1770 p. 138: Er bringt gemeinig-
lich 4 Junge zugleich zur Welt (from this work the statement is adopted by Couch, from whom Gunther probably has
his remark: It is stated to be viviparous, and to produce about four young at a birth [Introd. to the study of Fishes, [880
P- 3331 1 — aI1(1 - as moreover the verv nearest relative of the Greenland Shark, the Son/nioits rosiratus of the Mediterranean,
is known quite certainly to be viviparous, as also the somewhat more distant relatives, the Scymnus- species and the other
Spinaa'da , I, to be sure, think it most probable — I feel tempted to use a stronger expression — that also the Greenland
Shark, the other Somu/osas-s-pecies, must be viviparous.

i.ccording to Semper: Das Urogenitalsystem der Plagiostomen etc. (Arb. Zool. Zoot. Inst. Wiirzburg, 2, 1875) vasa
efferentia are in several Sharks already formed in the embryo; but I think it is doubtful whether they can be recognized here
without the assistance of the microscope, and it does not appear that Sir W.Turner has used a microscopical examination;
but he says that the mesorchium was so transparent that he must have seen a duct, if there had been one. The part of the
testis itself, which T. especially examined to trace a possible duct in it, can scarcely contain such a one, as it is evidently
the Vorkeimfalte of Semper, i.e. the part where the new ampullae are formed.

ON THE APPENDICES GENITAEES (CLASPERS) IN THE GREENLAND SHARK.

loped condition in the other (and it turns out to be very few) male specimens, mentioned as
examined by naturalists.

In this circumstance, in connection with the interpretations by Sir W. Turner of the genital appa-
ratus in both sexes, is most likely to be sought the reason of the idea that the Greenland Shark
only should be possessed of rudimentary copulatory appendages. This supposition has been
set forth by Professor Liitken in the communication on the propagation of the Greenland Shark, cited
on p. 3 note 2. In this paper Sir W. Turner's description of the reproductory organs both of the male
and female is reported with the following remark: < Of what use the copulatory members of the male
were was not evident; but perhaps these organs are in this species of Sharks rudimentary structures
without any importance? At all events I know no descriptions giving them a size like that found
in the Spiny Dog-fish or the Basking Shark . I must confirm the latter sentence myself. It was to
be expected beforehand that, if the male of this species had really copulatory appendages of proportions
relatively as those of other species, so prominent formations would scarcely have escaped the notice,
but would probably have been mentioned by one or more of the many earlier authors, who have
written of the North and the Northern nature, in which writings the Greenland Shark and the
catching of it bear a part, and of whom more, I suppose, have had the opportunity of knowing the
animal by autopsy.

However, I have in vain sought in authors as: Egede, Cranz, O. Fabricius, Scoresby,
Eggert Olafsen, Mohr, Olaus Olavius, Faber, Pontoppidan, Strom, Leem, Rosted,
Landt, and others; I find nothing concerning this point. Only Gunner us 1 ) mentions these organs,
which we have reason to take to be the external characteristics of the male , but in undeveloped
condition. Gunnerus had 3 male specimens, the largest not exceeding 5 ells (Danish) in length,
and the smallest being 2 s j 2 ell; the figure shows the appendages quite small, shorter than the fin-
membrane; besides it is evident from his description, that he himself justly thinks his specimens to
be young animals.

Later authors too do not mention appendages in more developed condition; they are on the
whole (as far as I know) only mentioned by Yarrell and by Malm. Yarrell 2 ) says of a specimen
described by Valenciennes 5 ): The fish was a male; the ventral fins and sexual appendages or
claspers very small . Valenciennes himself, however, says nothing of the sex, and does not at all
mention the appendages; he only says that the ventrals are small, so that possibly the cited remark
of Yarrell has it origin from a misreading. Malm n mentions two males, which he correctly declares
to be young, respectively of a length of i850 mm and i88o mm ; the length of the hjelpgenitalia» was in
both 25 mm ; they did not reach the end of the ventral fin. Only in one place I have found a statement
suggesting, that the authors in question have had the opportunity of seeing the appendages of the
Greenland Shark in a more developed state, viz. in M tiller and Heule s ). They divide the genus
Si yii/i/ us in two subgenera: 1) Scyiinnis (to which Sc. lichia and .S'. brasiliensis) , characterized among

M 1. c. p. 330 seq., pi. X, fig. 1, Lit. a. PL XI, fig. 1, Litt. a, a.

2 ) History of British Fishes, 3J ed., 2, p. 527.

3) Nouv, Ann. du Museum. 1, p. 455, pi. 20.

4) Goteborgs och Bohuslans Fauna. 1S77. p. 627, 629.

5) Systematische Beschreibung der Plaglostomen. 1841. p. 91, 93.

ON THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK. 5

other things by: Die mannlichen Anhange ohne Stachel , and 2) Lamargus (to which /.. borealis
|the Greenland Shark], L. Labor dii and L. rostratus) in which: die Mauucheu liaben einen Stachel an
den Anhangen . But whence have M. & H. this latter information? The work itself tells nothing
about it, and in none of the works cited is found anything about a spine on the appendage in
S. borealis (and no more in the other species).

After Professor Liitken having given the cited communication about the propagation of the
Greenland Shark the Museum of Copenhagen has got a male specimen of a length of 9 ft. (2835 mm ),
whose ventrals are preserved in the collection; also in this specimen the copulatory appendages are
verv small as hereafter mentioned, and so far they might serve as a corroboration of the advanced con-
jecture, that in this Shark these organs should be rudimentary and functionless.

As I, however, had some doubts of the correctness of this supposition --as also of the other
that the Greenland Shark should be oviparous -- I endeavoured during the last cruise of the Ingolf-.
to get fins of the Greenland Shark for examination, and as far as possible to procure reliable infor-
mations of this Shark in all respects. During a stay in the close of June 1896 in Dyrefjord, where a
manufactory for train-oil of the Greenland Shark is found, I took the opportunity of communicating
with a fisher of Greenland Sharks,* whom I for some time questioned by means of an interpreter.
The conversation was rather difficult, as the man was somewhat embarassed, only answered to my
questions, and would not speak himself or give his own opinion. However I got the information
that the fishermen know very well to distinguish between male and female, that «eggs> (i. e. the large
ovarial eggs) are only found in large specimens, and that the males are smaller than the females;
he had however never seen a Greenland Shark smaller than about 3 ells (Danish) r ). I drew a sketch
of the ventrals for him, and asked, if he had seen the appendages on the ventrals, which he affirmed;
then I promised him a reward, if he would obtain for me as many pairs of ventrals as possible, and
with as large appendages as possible, which he might preserve in brine, as also a whole and sound
male, as I supposed that I should be back in Dyrefjord about at the time, when he should return
to deliver his next cargo of liver, this, as is well known, being the only part of the animal made use
of. Circumstances however would that the Ingolf did not return on the Dyrefjord until the beginning
of August, and so I did not find the man again. But I found at the manufactory a great deal of
pairs of ventrals in brine, all with the appendages and with these in different stages of development,
together with a whole male, the last the fisherman had caught; he had during the whole time very
carefullv kept the last caught male for preservation, and had come on the Dyrefjord with a quite
sound specimen, which was also the very smallest he had got; but as I did not return in clue time,
also this specimen was put into brine. Apparently everything had kept very well by this mode of
preservation, the fins at all events excellently; but by the dissection of the whole Shark it soon became
apparent that all the internal organs were sadly damaged: the kidneys and the internal reproductive
organs were completely disorganized, so that nothing whatever was to be recognised; not even the
renal ducts that use to be rather resistant, were to be traced at all. I was thus disappointed in my

') Collett however states that specimens of a length of about 2 ft. sometimes have been obtained; probably
newborn youngs. Meddelelser om Norges Fiske i Aarene 1879—83, p. 118. Nyt Mag. f. Naturv. vol. 29.

6 ON THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK.

hope of being able to give a good account of the structure of these organs, and must be content to
give informations of the external copulatory organs.

The whole Shark was about 8 ft. (2 m 50 cm ) in length, and its ventrals, as also their appendages,
were smaller than any of the other cut off ventrals and their appendages, which latter were also
much more developed; unfortunately no statement of the length of the respective animals was given.
But if we start from the supposition, which I think most likely, that the ventral proper grows in pro-
portion to the animal itself, we can with some certainty calculate the size of the animals, to which
the cut off fins have belonged; and judged by that they have all been large animals between 3 and
5 metres, the largest at all events upwards of 6 ells (Danish).

I am not able to decide with perfect certainty, if an}- of the obtained ventrals have the appen-
dage so large and developed, as it possibly can be; but at all events these organs are so far developed
in the largest specimens that they will scarcely change their structure in any considerable degree,
even if they become somewhat longer. In the largest fins the free end of the copulatory organ
reaches about 5 cm farther back than the point of the fin-membrane itself; in the somewhat smaller
ones 3 — 4 cm , and in two a little smaller still about i cln behind the point of the fin. In the smallest
specimen finally (the above mentioned animal 2 m 50 cm long) the' point of the ventral on the contrary
reaches 2 — 3 cm farther back than the point of the appendage. Between this last specimen and the
immediately preceding the above mentioned specimen of the museum (which however is partly skele-
tonized) may be placed with regard to size and development. Here accordingly we have a series
showing the stages in the growth of these organs, well known from the other Sharks, from small
short rudiments, shorter than the ventral itself, to a more or less considerable length beyond the
inner edge of the ventral. Thus every idea of the Greenland Shark differing from other Sharks in
only possessing rudimentary ventral appendages must be dropped.

About the remaining external features of the organ I shall confine myself to state, that its
whole dorsal surface (i. e. the surface which in the natural position is in contact with the ventral
side of the body) as well as the adjoining part of the fin itself is quite naked and smooth without
dermal teeth, which is also the case with the medial surface, where those of the same pair are in
contact, while the ventral surface (as in the remainder of the fin) is clothed with dermal teeth,
however more sparsely and sparingly towards the point, the outermost part of which is naked and
quite soft. Otherwise these organs are in their developed state stiff and hard 011 account of the
strong internal skeleton. On the lateral side of the end is felt through the skin a particularly hard
and movable part of the skeleton, and in most of the specimens this part is naked and appears as
a pointed, polished thorn or spine. I can however assert with certainty that in all the specimens,
I have brought home, it has only been laid bare by the skin on the spot being torn; it is also seen
cpiite covered in the right clasper of one of the largest specimens. I suppose, however, that before
the member comes into function, or at the function, this spine is uncovered; in fully developed
appendages of Acanthias and Spinax at all events both the corresponding part and one or two more
pails of the skeleton protrude naked, uncovered by the integument; and in the circumstance that in
all these tins the spine surely only has been set free by damage or by bad preservation, I find
a positive intimation of their appendages not yet having reached their greatest development. This

ON THE APPENDICES GENITALIS (CLASPERS) IN THE GREENLAND SHAKR.

spine is still plainly felt in the somewhat smaller fins, excepting the two smallest; in these evidently
it has not vet been calcified, no more than most of the other parts of the skeleton, characterizing
the end or terminal part of the developed organ; therefore these small appendages are npon the
whole rather soft to the feeling and with flexible ends.

The form of the developed appendage is straight, somewhat dorso-ventrally flattened ; a distinc-
tion may be made between the considerably longer proximal part, which might be called the shaft,
and the short distal part, the terminal part, which is free of the fin, and, as will be more parti-
cnlarlv bespoken hereafter, possesses a certain limited mobility; the largest breadth is found imme-
diately before the terminal part; on the dorsal side, somewhat nearer to the lateral than to the medial
edge, is seen the peculiar cleft, the appendix-slit, which is found in all Selachians; it reaches
to the posterior end of the member, and leads in the free part of this into a deep canal, more
anteriorlv into a glandular bag, which, like a deep pocket, at the base of the appendage goes round
to the ventral side of the fin, and here under the skin reaches — according to age and development —
a longer or shorter distance towards the pelvis. The inner walls of this bag are smooth, partly
pigmented, and from their epithelium is secreted a peculiar fluid, which when coagulated is tallowy,
but whose function is not certainly known. This bag, as to its origin, is simply a folding in of the
outer skin 1 ); it is surrounded with muscles, able to press the secretion into the canal and through
the slit to the exterior. The inner (medial) lip of the slit is immovable and cannot be displaced,
while the outer (lateral) one till near the terminal part consists of soft tissue, and is therefore easily
opened, so that a finger may be introduced into the bag; but at the end of the shaft, immediately
before the terminal part, all distension is prevented by the inner skeleton, which is found here, and
straightens the slit, so that it becomes very narrow; to the distal side of this straightening, in the
terminal part ifself, the canal may again be opened, and it will open spontaneously, if the terminal
part is bent a little in the ventro-medial direction, in which case the spine will at once erect.

The following measures referring to the largest appendages, may be added:

Length from the anterior border of the cloaca to the terminal point of the appendage 24 — 26 cm .

of the terminal part of the appendage 5 — 5'5 cm .

Breadth of the appendage before the terminal part 3'3 — 4 cm .

Length of the slit i6 cm .

of the part outside the fin 6 cm .

Part outside of the point of the fin-membrane 5 c,n -

The skeleton (pi. I, fig. 1—9). The skeleton of the ventral fin in the male consists of 1) the
pelvis, 2) the axial part or the stem, wdiich laterally wears 3) the rays, and as a continuation
4! the skeleton of the appendage.

The structure of the pelvis is as commonly in the Sharks, it consisting of an unpaired, some-
what arcuated cartilage, the surface of which is rather slightly calcified ; it has the greatest thickness

' I have followed its development in embryos of Acanlhias , as has also been done by Petri: Die Copulations-
organe der Plagiostomen. Zeitschr. f. -\viss. Zoologie, vol. 30, 1878.

8 ON THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK.

in the middle, and here projects from the posterior edge a clumsily rounded process. The stem of
the ventral articulates by its principal piece, the basale, (pi. I, fig. i B), with the lateral end of the
pelvis, as do also a pair of the foremost rays. The foremost ray (i?) is always short and
big, shaped like the blade of an axe, whose head articulates with the pelvis, the hindmost corner of
the blade with two small terminal joints; it bears the second ray, which is accordingly out of connec-
tion as well with the stem as with the pelvis; sometimes it is proximally coalesced with H. The third
ray has pressed so far forward, that it articulates both with the stem and the pelvis. Most of the
other rays are more or less straight, cylindric, distally a little flattened (especially in the foremost
ones); the two (less frequently three) hindmost are always somewhat bent, so that the convexity turns
dorsally, owing to the fact, that the glandular bag from the dorsal side passes under them to the
ventral side of the fin. These two hindmost rays are often more or less united, sometimes almost
quite coalesced. The foremost rays (more than half of them) have three joints, then follow some (3)
with two joints, and the last (3) are never jointed. The number of rays varies from 12 — 16 1 )\ com-
monly one fin of the same pair has a ray more than the other, and a rather considerable variation
is found in the more special relations of the rays, in their mutual coalescing 2 ), their articulation, and
distal dichotomy; sometimes an extra ray is inserted, not reaching the stem; such extra rays have
not been counted in the numbers given , and they do not occur symmetricallv in both fins. Such
variations are also known in other Sharks 3) , and I shall not here enter into further details , as they
are of no importance for the examination in question.

The stem consists of 1) a large and big principal piece, Basale nictapterygii (/>'), to which
most of the rays are attached; its inner edge is almost straight, only slightly concave, the outer edge
is convex; 2) a short piece (b 2 ) directly continuing the foregoing; 3) generally is on the medial side
inserted, as it were intercalated, a little cuneiform piece (b T ). The piece b 2 bears the two hindermost
rays, so that the last but one is articulated at its proximal extremity, and here also touches the ba-
sale, the last at its distal extremity, where it has also a little articular surface with the proximal
end of the stem of the appendage. Finally is found 4) a rather considerable piece (/J) placed on the
dorsal side of the stem in such a way, that it is proximally connected with the latero-dorsal corner
of the basale by a little articular surface, and distally by a longer, obliquely placed articular surface
with the latero-dorsal edge of the anterior end of the appendix-stem (fig. 2 at x). This piece /? is
rather thick, dorso-ventrally somewhat flattened, has a convex medial edge, and a straight lateral
edge; posteriorly it is somewhat more pointed than anteriorly; the foremost part of the convex edge
is connected with the dorsal side of the piece b, ; it has no articulation at all with any of the rays-*).
Between the lateral corner of b 2 , /?, and the appendixstem 5) a little piece £ 3 is sometimes intercalated.

Then follows 6) the appendixskel eton. Its chief piece (tab. I, fig. lb, fig. 2, 3) evi-
dently belongs to the stem, and is placed in immediate continuation of the foregoing pieces, with

) In two females I have found the number respectively 15—17 and 16—17 on the two sides.

I In one specimen separate, independent pieces of cartilage have been developed; they are placed across, and near
the outer end of the rays they connect two and two of these.

1 Comp. Gegenbaur: Ueber das Skelet der Glieduiaassen der Wirbelthiere im Allgemeinen und der HintergHed-
maassen der Selachier insbesondere. Jen. Zeitschr. 5 Bd., 1870, p. 435 seq.

1 l'.\ the choice of the letter-marks I have intended to point out, that all these parts belong to the stem-skeleton.

ON THE APPENDICES GENITALES (CDASPERS) IN THE GREENLAND .SHARK. g

which it forms an — to be sure very obtuse — angle. In a fully developed skeleton the chief piece is
loneer than the b a sale; in the largest specimens at hand the ratio is: — = c. — ; on the medial
side it is rounded, in the foremost third part somewhat dorso-ventrally flattened; the 'lateral sur-
face (/) is more or less distinctly bounded from the other surfaces; it is only in the fore part
somewhat rounded, posteriorly it is flattened, and the hindmost part is somewhat hollow; on the dorsal
side this lateral surface is in the whole length of the piece sharply limited by a thin, elevated, hard
calcified ridge (fig. 2, 3, AV), anteriorly beginning as quite low, posteriori} - becoming higher and higher,
as well as thicker, and bearing in the posterior half an edge, folded to the dorsal side, (irregularly
indented, and collarlike; 011 the ventral side (see fig. 3) the lateral surface is in the greater part of its
extent much more indistinctly bounded by an evenly rounded eminence, which is not harder than
the common stirface; in the posterior part, however, rises rather suddenly a short, calcified, strong
ridge or plate, which in the shape of a large foliaceous process folds over to the dorsal side, where
it approaches rather near to the opposite edge (fig. 2, 3, Rv). The free edge of this folded process
is thickened, and irregularly rugged. The described elevated ridges or plates in connection with the
flatly hollowed hindmost part of the lateral surface forms the place of part of the appendix-slit or
the excretory duct of the gland-bag; these hard parts of the skeleton it is, that, as mentioned on
p. 7, prevent a distension of the appendix-slit.

Immediately behind the end of these calcified ridges the chief piece continues as a thin, round,
finger-shaped elongation, the end-style (fig. 1, 2, 3, g); it is soft, or at all events at its base quite
devoid of calcification, while farther out a slight surface-calcification may be found. Else the chief
piece is everywhere calcified on the surface (being anteriorly somewhat rough for the attachment of
the muscles), and more calcified than the basale and the rays, but the above mentioned ridges
(AV, Rv) are completely calcified and hard. When such a chief piece is dried, these ridges
therefore will not shrink, but rise distinctly as independent parts. By a close examination of an
undried chief piece the boundary Hues of these calcified side-parts may also be distinguished, and thus
we shall arrive at the same result: the chief piece is composed of three parts, viz. the
appendix-stem {b), posteriorly becoming lanceolate, medio-laterally compressed, and ending as a
slender, thin, (at the base) uncalcified end-style, and two calcified marginal cartilages, one long,
slender, dorsal, the other shorter, broader, ventral (AV, Rv).

To this chief piece are attached a number of terminal pieces, more or less movably joined
to each other and to the chief piece. Of these pieces two join the posterior borders of the marginal car-
tilages and the end-style of the stem, and form, as a kind of continuation of the marginal cartilages, the
dorsal (dorso-medial), and ventral (ventro-lateral) borders of the hinder part of the appendix-slit; these
two pieces are here called respectively the dorsal and the ventral terminal piece (Td, To).

The dorsal piece (fig. 1 Td, fig. 4, 5) is the smaller one; it tapers to both ends, most to the post-
erior; on the exterior (medially) it is somewhat rounded, with a sharp lateral edge, a little denticulated,
towards the appendix-slit slightly hollow in the foremost two third parts; the thick medial edge is
by means of connective tissue closely connected with the end-style, the anterior end with the dorsal
marginal cartilage. It is completely calcified, and the surface, especially towards the terminal end, is
rugged and rough.

The Ingolf-Expedition. II. 2. 2

IO ON THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK.

The ventral terminal piece (fig. i Tv, fig. 6, 7) is considerably larger; the surface towards the
appendix-slit is deeply hollow like a trough, the external, ventral, surface is rounded, and has laterally
a winglike, sharp process; it is also completely calcified, and a great part of the surface is irregularly
furrowed and rugged. The one anterior edge of the trough articulates with the ventral marginal
cartilage, by the inner, ventral, edge it is connected with the style.

Between this piece and the overlapping plate of the ventral marginal cartilage is seen a
third terminal piece (fig. 1, 7",), the thorn or spine (fig. 8, 9). It is, like the other pieces, quite
hard, and the proximal end is somewhat head-shaped with a smooth surface, almost like an articular
surface; else it is for a great part very irregularly rugged and furrowed, but the outermost point is
glossv and smooth, dentine-like; the whole thorn is longitudinally somewhat twisted.

Besides these fully developed terminal pieces indications of two more are to be seen, viz. a
thin, narrow lamella, only calcified in spots, joins the lateral edge of Td, and supports the edge
of the dorsal lip of the appendix-slit; anteriorly it reaches somewhat beyond Td; this indicated piece
is here designated as Td z (comp. pi. Y, fig. 61, 62); the second piece is a very firm and strong fibrous
tissue, joined to the anterior dorsal edge of the piece Tv, and without distinct borders merging into
the aponeurotic covering, connecting the thorn, the piece Tv, and the overlapping plate of the mar-
ginal cartilage, and serving for insertion of part of the muscles (see pi. V, fig. 61, 62, Tv z ); in this
latter piece a calcification has commenced, indicating perhaps, that it might become a separate termi-
nal piece, which I shall designate as Tv, (comp. other Plagiostomes for iust. Spinax). As these two
last mentioned pieces are, as it were, still developing, I suppose, that even the most developed of the
appendices in hand cannot, in a stricter sense, be said to be full grown yet; but as the piece Tv 2 also
in some other Sharks (f. inst. Acanthias) is found only indicated and uncalcified, even in quite deve-
loped appendices, my supposition is not quite reliable.

The whole of this terminal skeleton, composed of the terminal pieces and the end-style of
the stem, is movable to a certain degree; as to further details on this point the reader is referred
to p. 14.

By examining the appendix-skeleton in the earliest stages of development we find that
originally it is composed of only one single piece, being that, which above is termed the appendix-
stem. This 1 in the specimen from Iceland, 2 m 50 cm long, and in the specimen from the Zoological
Museum, 9 ft. long) is still quite soft, shorter than the basale, anteriorly rounded, posteriorly lance-
olate, the edges of the lancet being placed almost dorsally and ventrally , and ends as a thin style
(see fig. 2 in the text p. 19); thus mainly rendering the form of the chief piece minus the marginal
cartilages. Of these latter as well as of the terminal pieces no trace is found. In somewhat more
advanced stages, where the appendix-stem is as long as, or a little longer than the basale, the three
terminal pieces and especially the thorn are very well to be distinguished, while the marginal cartilages
still are absent, or, at all events, in the fibrous tissues, occupying their place, no calcification or distinct
bordering of such cartilages is to be found (not even of the overlapping plate). In still a little
mure advanced stages also the marginal cartilages are found in the same shape and with the
same bordering as in the most developed, but the boundary lines between them and the stem are
much more distinctly marked; they are calcified, but are still soft enough to permit of easy cutting;

on THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK. I(

to the naked eve the section shows a particular fibrous texture (as in sections of the terminal pieces),
and a whitish colour, distinguishing it distinctly from a section of the appendix-stem or any other
part of the skeleton proper, for inst. a ray or the basale, the surface of which will be hyaline. From
these developmental facts it will appear with all desirable distinctness, that the marginal carti-
lages and the terminal pieces are secondary parts of the skeleton, developed in the
tissues surrounding the primary skeleton, properly so called. Tims of the appendix-skeleton only
the appendix-stem, the piece b, belongs to the primary skeleton.

To resume what is said about the appendix-skeleton in the Greenland Shark:

The appendix-skeleton consists of a chief piece and terminal pieces movably connected with
it; the chief piece is formed by the coalescing of the appendix-stem with two secondary calcified
cartilages, the marginal cartilages; the appendix-stem belongs to the primordial axial skeleton of
the ventral fin, being the terminal joint the extremity of which remains soft; the terminal pieces
are all secondary calcified cartilages.

The muscular system (pi. V, fig. 58 to 62) follows the type, which has been described in
Acanthias by v. Davidoff 1 ); this type, however, has been founded on the structure of the ventrals of
the female; the rather considerable differences from it are due to the copulatory appendages, for
the special use of which special muscles have to be developed. Distinction may be made between:
I) The fin muscles proper, and II) the muscles of the appendage; as, however, some of the former
spread over part of the appendage, this distinction cannot be made quite distinct.

I. In the fin -muscles proper may be distinguished, as v. Davidoff and the earlier
arithors do, between the muscles of the ventral and those of the dorsal side; they are anta-
gonistic, the former adducting the fin, and removing it from the abdomen, the latter abducting the
fin, and pressing it against the abdomen.

1) The ventral muscles of the fin consist of a) a medial muscular mass, chiefly reaching
from the pelvis to the stem-skeleton of the ventral, with laterally and obliquely -posteriorly directed
bundles of fibres, and b) a lateral mass, the muscles of the rays, issuing from the stem-skeleton, and
following the rays to the fin-membrane.

a) This powerful groirp of muscles (pi. V, fig. 58 — 61, A and E) in so far does not wholly be-
long to the ventral side, as, besides forming the medial edge of the fin, it is also seen on the dorsal
side. Looking first at its ventral side we find its origin covering almost the whole ventral surface
of the pelvis: between the fin-muscles of the two sides only a triangular piece of the pelvis is to be
seen in the middle anteriorly, from the top of which a narrow uncovered streak runs backward to
the end of the above (p. 8) described process; from this issues further backward in the linea alba
an aponeurotic streak (fig. 58, s), which continues the pelvis, and serves as attachment for part of the
same muscular mass. The superficial ventral part is for the greater part composed of distinct bundles
of muscles, enveloped in rather firm sheaths of connective tissue, and mostly corresponding in number
and direction with the muscles of the rays; but this composition of isolated bundles is effaced anteriorly-
laterally and posteriorly-medially.

Anteriorly the fibres running obliquely from the pelvis towards the outer margin of the fin

■i Beitrage zur vergleichenden Anatotnie der hinteren Gliedmasse der Fische. Morphol. Jahrbuch. 5 Bd., 1S79, p. 454 seq.

2*

I2 ON THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK.

form a rather solid mass spreading from the fore edge of the pelvis over the broad ray R. The fore-
most of the following distinct bundles of muscles cross the ventral surface of the basale reaching as far
as to the horny filaments of the fin-membrane, ending here in a tendinous mass; the following bundles
only reach to the basale where they are inserted with tendinous ends, from which tendinous part the ray-
muscles originate as a prolongation — however, when we look farther backwards, with a distinct inter-
position of a narrow stripe of the basale. Between the said foremost bundles, continuing immediately in
the ray-muscles, and those attached to the basale, a gradual transition is found, a tendinous part in
the superficial layer of the bundles being inserted on the place of transition.

The hindmost and medial part of the muscle A is not composed of isolated bundles, but its
fibres running rather straightly backwards form a solid mass, inserted on the distal end of the basale,
on the pieces 6 U and 6 2 , and on the proximal end of the chief piece of the appendage (Z>).

The whole muscular mass, as mentioned, is of a considerable thickness; its deeper part which
is also seen from the dorsal side, is not divided into separate bundles; this deeper, more dorsal, part
originates from the rounded posterior surface of the pelvis, and even reaches to its dorsal surface; it
is inserted along the medial side of the basale and the following joints inside the insertion of the
described superficial ventral layer.

With this muscle A is closely connected another (pi. V, fig. 59 and 61, E), chiefly seen from
the dorsal side. It originates on the medial side of the basale, a little before the middle, its fibres
crossing those of the muscle A, and spreading over the appendage; as above the knee of the latter
the fibres run oblicpiely across the medial edge of the fin and on to the ventral side, part of the edge of
this muscle will consequently be discernible on this side (pi. V, fig. 58 and 60 E). It is spread like a
cloak over the chief muscle (D) of the appendage forming a rather thin plate and growing thinner from
the ventro-medial edge laterally (cp. fig. 1 in the text); its fibres are attached, partly along the narrow
ridge, formed by the dorsal marginal cartilage along the appendix-slit (fig. 61 nf) partly, distally, to a
thin, firm aponeurosis (fig. 61 a), covering the muscle Z>, and attached to the elevated distal part of
the dorsal marginal cartilage {Rd). In somewhat older animals with well developed appendages this
muscle E is as well proximally as distally distinctly separate; in young animals, however, with
only little developed appendices (fig. 59) the distal part is still very distinctly marked, but the proximal
part is less sharply separated from the large muscular mass , i ; numerous bundles coming from the
pelvis and the aponeurotic streak s unite with those from the basale, and numerous bundles from the
basale run over among the former and reach to the proximal end of the appendix-stem.

The above described muscular group consisting of the muscles .1 and E, will, according to
circumstances, be able to act in two different ways; these muscles will, when the antagonists of the
dorsal side are not contracted, move the fin from the abdomen, and at the same time draw its inner
edge towards the median line, thus moving the two fins towards each other; and when the dorsal
antagonists act on the fin, they will move the appendix only, towards the median line, thus
acting as extensors for the appendix; the latter action will be facilitated by the muscle E acting
lather distally on the appendix (an effect as to the opening of the appendix-slit is of course out of

ON THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK. ^

the question). Consequently I design the large chief muscle A as Mus cuius adductor [et depressor]
pinna- (rf appendicis\ the muscle £ as Muse, extensor (appendzas) 1 ).

b. The ventral muscular system of the rays (fig. 58, 60, Ra) is composed of distinctly separated
bundles of fibres, or independent muscles in number corresponding with the rays they follow; only
anteriorly the independence of the ray-muscles, as mentioned above, is concealed bv coalescence with
the lateral bundles of Muse, adductor, coming from the pelvis. The ray-muscles originate on the
ventral surface of the basale and the piece b 2 > and run laterally backwards in an oblique direction,
each following its ray, but without reaching the end of it; they only reach the horny filaments (the
two layers of which comprise a rather considerable part of the lateral ends of the rays) and here
pass into tendinous tissue. The hindmost ray-muscle is rudimentary; it does not originate on
the stem-skeleton, but on the last ray but two, and passes to the last but one and on to the fin-
membrane.

2) The dorsal muscular system of the fin proper (pi. V, fig. 59) is composed of a) a super-
ficial part originating from the lateral muscles of the body, and b) a deeper-lying part originating from
the stem-skeleton.

a) On a part of the body, corresponding in length to the connection between the body and the
fin, a system of distinct muscular bundles (O) originate in the aponeurosis covering the lateral muscles
of the body, and run obliquely outward and backward to the horny filaments, where they pass into ten-
dinous tissue; thus their outward border corresponds to that of the ray-muscles on the ventral side,
being considerably distant from the ends of the rays. The hindmost of these bundles are directed
straight backwards, corresponding to the direction of the last of the rays. Furthermore from the
inner side, the side towards the muscles of the body, of the said system some bundles of fibres (O 1 )
originate running obliquely backward and inward, and attached to the hindmost half of the basale
and to the dorsal piece /J; thus the whole system originating from the lateral muscles, is, as to the
hinder half, arranged in a feather-like or fanshaped way.

b. Quite covered by the superficial layer just described the deeper layer of the dorsal ray-
muscles (fig. 59, Ra) is found. These muscles originate from the dorso-lateral side of the basale and
of the piece b z as well as from /?, and are seen as distinct bundles corresponding in their number and
direction to the rays; they pass into tendinous tissue immediately before the lateral ends of the bundles
of the superficial layer, so that the latter reach a little way farther on the rays. However, these
two layers are not quite sharply separated, bundles of fibres from the superficial layer reaching to the
deeper, and connecting with it; on the hindmost fin-rays the bundles of the deeper layer cross those
of the superficial one, this latter spreading in a fanshaped way from the attachment to the body.

II. Besides the described separate parts of the fin muscles connected with the appendix

') The muscle which in Acanthias ami other Selachians corresponds to the muscle A, is by Petri called: Flexor
f>terygopodii\ but there are several objections to this name. Firstly, the muscle does not only act on the appendix, but on
the whole fin (it is also found in the female), and next it cannot well be called the flexor of the appendix, as it is more
properly to be regarded as the extensor. The flexion of the appendix is, I suppose, effected by means of the M. compressor
sacci, the muscle of the glandular bag (fig. 58, 61, S ), of which more hereafter, together with the muscular layer originating
on the body itself ifig. 59 and 61, O).

j , ON THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK

other muscles are found, more especially belonging to this organ, it being inside the skin quite
surrounded by muscles except the terminal part. In this muscular system may naturally be distin-
guished between: i) The muscles of the chief piece, and 2) those of the glandular bag.

1) The first part (pi. V, fig. 58— 62, D) is composed of one single muscle wrapping in a cloak-
like manner the whole of the chief piece from the dorsal marginal cartilage to the ventral one,
and to the rounded edge formed by the appendix-stem itself along its lateral surface above this
short marginal cartilage; the part of the chief piece situated between these bounds, the lateral
surface is for the greater part covered by the muscles of the glandular bag (see fig. 1). The

large muscle D is thickest along the medial side of the
appendix, and is chiefly composed of longitudinal fibres
arising from the whole length of the chief piece; from
the foremost part of this, below the knee , arise some
specially powerful bundles, and consequently this part
of the surface of the skeleton is very rugged; also from

the lateral edges arise numerous fibres and bundles,
Fig. 1. ft '

Part of a transverse section through the appen- and distally several bundles come from the covering

daee of the Greenland Shark (about 26"™ behind • , , TT <■•_ /- > /-« -,• . .-, r

" , ' ,. , , aponeurosis a (see pi. V, fig. 61 . Corresponding to the form

the beginning of the appeudix-sht). the appen- 1 x ° r °

dix-stem; D M. dilatator; E M. extensor; S M. com- of the appendix-stem this muscle tapers distally, and its

pressor; af the appendix-slit; r a rav; // horny ... r ., . , , - , , T .

filaments hindmost fibres reach to the base of the style, it is

inserted in the firm aponeurosis covering the marginal carti-
lages and the whole terminal part, and thus it acts on the style and the two terminal pieces Td and
Tv. In contracting it bends the style medially forward at an obtuse angle to the chief piece, where-
by the two terminal pieces are also moved; at the same time the thorn is erected on account of its
connection with the other terminal pieces, especially Tv, and stands out laterally; as a consequence the
distal part of the appendix-slit situated between these movable pieces, is dilated to a rather consider-
able degree. I therefore (like Petri) design this muscle as M. dilatator.

2\ Among the muscles of the glandular bag I do not only class a) the muscles immediately
wrapping this organ, but also b) some portions (fig. 61, 62, S) arising from the hindmost rays, and
forming, in my opinion, with the glandular bag an insolvable whole, only artificially to be detached
from it. The glandular bag, as I understand it, has its origin from an invagination of the skin
into a muscular mass laterally covering the stem-skeleton in the appendix; by the further growth of
this invagination on to the ventral side of the fin part of the muscular mass was brought along as
a kind of wrapping of the bag and developing further together with it. Consequently this wrapping
cannot be regarded as dermal muscles but belongs to the skeletal muscles; it is also composed of quite
the same striated fibres as these; its original relation to the stem-skeleton may, in the fully developed
organ, be seen in the still existing attachment along the lateral surface of the appendix-stem (see the
transverse section, fig. 1 in the text).

a. The glandular bag (pi. V, fig. 58, 60 S) is seen on the ventral side of the fin, where it
reaches forward covering a .smaller or larger part of the ray-muscles, according to the development
of the whole appendage; while in the youngest specimens it only reaches very little beyond the

ON THE APPENDICES GENITALES (CLASPERS) IN THE GREENLAND SHARK. 1C)

knee between the stem and the chief piece of the appendix (cf. fig. 58), in the most developed it
reaches almost half way towards the pelvis (cp. fig. 60). As the glandular bag in most of the other
Sharks, which I have examined, reaches still further, generally even far beyond the pelvis, there is
reason to suppose that in none of the ventrals of the Greenland Shark in hand the whole copulatory
origan has reached the greatest development, which was already intimated by the description of the
skeleton of the terminal part.

The connective tissue, investing the muscle-sheath of the glandular bag, is continued on all
the specimens as a very thin membrane between the skin and the ray-muscles almost to the pelvis;
this membrane may easily be separated as well from the skin as from the muscles, but in the
specimens in hand it (perhaps as a consequence of the preservation in brine) is very fragile; it contains
no striated muscular fibres.

While the dorsal muscular wall of the glandular bag has no intimate connection at all with
the part of the fin before the < knee -- only a loose, soft connective tissue here joining the bag to
the ray-muscles - it is otherwise at the proximal end of the chief piece, part of the muscles of the
bag being inserted on the lateral surface of this part of the skeleton, covering it wholly, and following-
it quite down to the terminal part; other fibres attach to the last ray along its medial edge; and
some fibres arising from this spot and from the ventral surface of the two last rays, pass into the
dorsal muscular wall of the glandular bag and continue it to the ventral marginal cartilage, where
they attach to the connective tissue of its inner side.

The direction of the fibres of the dorsal muscular wall of the bag otherwise corresponds to
that in the ventral wall; as shown in fig. 60, the fibres radiate from the point, where the connection
with the skeleton anteriorly ceases; along the medial side they run almost in a parallel direction with
the axis of the bag and the appendage, but else on the broader part of the bag they spread in a
fanshaped manner to the lateral edge; on the hindmost narrow part they run entirely straight back-
ward, and here a few bundles pass into M. dilatator. This arrangement agrees very well with that,
which fibres originally directed from before backwards, might be supposed to get by being pressed out
of their position by an invagination protruding from the region between * * in fig. 60. A separation
of the muscular wall of the bag into two distinct layers is quite out of the question. With regard to
Acanthias Petri (1. c. p. 316) has stated that the muscular wall of the bag consists of two layers, an
outer one of circular muscles, and an inner one of longitudinal muscles; a separation and arrangement
of such a kind however, is not found in Acanthias. any more than in Spiuax or the Greenland Shark.
Neither can I admit that the words of Petri (I.e. p. 317) are correct: Die Muskelschicht der Druse
wird nicht mit eingestiilpt, soudern sie differenzirt sich allmalieh aus der Bindegewebsschicht nach
der Einstiilpung. iCp. also I.e. p. 328). In my opinion, as before has been shown, it admits of no
doubt that the muscles of the bag are simply borrowed from the original muscular system of the
skeleton 1 ); in the earliest stages of Acanthias -- male embryos of a length of 15°'" -- which I have
been able to examine in this respect, the muscles around the rudiment of the glandular bag are
already as distinct as those surrounding the stem of the chief piece, and the muscular layer of

"i This is corroborated with particular plainness by the arrangement in the Holocephales.

r g ON THE APPENDICES GENITALES iCLASPERSl IN THE GREENLAND SHARK.

the bag has already been pressed towards the ventral side as well as the other surrounding layers
of tissue.

b. Intimately connected with the other muscles of the glandular bag is found a powerful
muscle (pi. V, fig. 59, 61 and 62, S), seen on the dorsal side, where it forms the lateral lip of the long
slit (of), which is the entrance to the bag. It takes its origin from the two hindmost rays (sometimes
also having bundles from the last but two) as also from the lateral surface of the piece /?, covered
bv the superficial layer (O) coming from the muscles of the body; it is inserted in the tendinous
tissue passing over the head of the thorn (T), and firmly connected with the proximal end of the
terminal piece Tv, especially with its edge; in this tissue is found imbedded several firm, fibrous
portions, which partly calcify, and probably in more developed stages — form a separate piece

(Tv 2 ). In the hindmost part this muscle is completely fused with the distal part of the muscles
of the glandular bag, and anteriorly it forms a whole with the above mentioned bundles of the dorsal
wall of the bag, which arise from the ventral side of the two hindmost ravs; in the interspace a
kind of separation is effected by the attaching of the fin-membrane, the connective tissue of which
wedges in between the lip muscle » and the wall of the bag itself. This muscle acts antagonistically
to M. dilatator, which in a preparation is easily seen by pulling it: thus when M. dilatator by contracting
has dilated the groove between the terminal pieces, as described above, and the thorn stands out, the
contraction of this outer lip-muscle * of the appendix-slit will again straighten the groove by especially
acting on the piece Tv, and at the same time carry back the thorn , so that it will lie against the
piece Tv.

I find the same muscle in all other Plagiostomes, but in very different stages of development
(cp. the following). Petri has mentioned it in Acanthias, but as M. levator of the thorn (I.e. fig. 5,
B, C, T, ml); he says: ?Er inserirt sich hiuten vermittels eines starkeu, sehnigen Bandes am vorderen
Theil des Spornes ( the thorn ) und hat allein die Aufgabe diesen zu heben. This, however, is quite
incorrect: it is not inserted on the thorn, even if its tendon of course by looser tissue is connected
with the proximal part of the latter, but on the piece Tv (!>'" in the figures of Petri), of which piece
Petri's interpretation is quite wrong (cp. the following); and it does not assist the J/ dilatator, nor
raises the thorn, but it counteracts the M. dilatator, and therebv becomes a J/, depressor of the thorn!
The carrying back to the position of rest of the terminal pieces is in the Greenland Shark and
Acanthias not exclusively brought about by an elastic reaction of the tissues between the firm parts
of the skeleton, as asserted by Petri (I.e. p. 303), but this reaction, which certainly exists, is also
supported by the action of muscles belonging to the glandular bag, or, at all events, forming part of
its muscular system. Taking it for granted that the appendix genitalis by the copulation is really
introduced into the cloaca of the female, I imagine the following act to take place: the appendix is
guided and brought into the cloaca by means of the muscles belonging to and arising from the fin-
muscles proper; next the J\f. dilatator will come into function, and, by its dilating the terminal parts,
fix the appendix in the cloaca, and then the muscles of the glandular bag will evacuate its contents
into the furrowshaped, in the appendix itself situated part, the walls of which at the same moment
will contract, at the same time ejecting the secretion and letting go the firm hold of the apppeudix.
As I think the chief action of the muscular wall oi the glandular bag to be the ejection of the

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS x j

secretion, I design it — including the described «outer lip-muscle of the appendix-slit — as Musculus
compressor (sacci).

II.

The Ventral Appendages in other Selachians.

For comparison with the facts found in the Greenland Shark, I have examined as man}- other
forms of Selachians, as I have been able to get the material for, being soon convinced that the repre-
sentations, hitherto found in the literature, gave only a rather incomplete insight into the structure of
these organs, and only to a small degree were to be used comparatively.

The greater part of my material has consisted of well preserved ventrals, a less part only of
skeleton parts, dried or preserved in spirit, which the director of the collection of Vertebrata of the
Zoological Museum, Professor Liitken, has been kind enough to place at my disposal. The following
description has been divided into three parts of very different extent, of which the first will give a
short general account of the copulatory appendages in the Selachians in general, the second a more
particular description of the forms, on which this general account has been based, and the third will
as a conclusion contain some short remarks as to what for the present may be regarded as tolerably
certain concerning the function of these organs. That the particular description will treat more of
the skeleton and less of the muscles is occasioned by the relatively small variation of the latter.

i. A General View of the Copulatory Appendages in the Selachians.

As to the outer form, the same outline is found in the copulatory appendages of all Se-
lachians: it is always the inner part of the fin which is prolonged, and formed into an appendage,
and this appendage may be more or less free of the fin-membrane; it is most separated in the Holo-
cephales, least so in some Sharks; it always consists of a, longer or shorter, proximal part, the shaft,
and a, generally shorter, distal part, the terminal part, this latter being always free of the fin-
membrane, and (at all events in the Plagiostomes) possessed of a certain mobility.

On the dorsal side of the appendage, sometimes, however, quite laterally, a deep furrow or
slit, the appendix-slit runs longitudinally, to the posterior end; the edges or lips of this slit can
always be opened, at least in two places, viz. at the foremost beginning of the slit in the shaft, and
behind in the terminal part; frequently the slit can be widened in a considerable part of the shaft
(Somniosiis, Acant/iias, Spiuax, a. o.); there is, however, always a part of the slit, in which widening
is prevented by the inner skeleton, or where the lips cannot at all be separated, or sometimes even
may be coalesced (the latter in Scyllium and Pristiurtis); the part of the slit situated in the terminal
part can (at all events in all Plagiostomes) be widened by muscular action, and again narrowed by-
elastic reaction, sometimes assisted by muscular action. The appendix-slit is the duct of a glandular
bag which is surrounded by muscles, and in all Plagiostomes with its greater part situated on

The Ingolf-Expedition. II, 2. 3

r g ON THE APPENDICES GENITALES iCXASPERS) IN THE SELACHIANS.

the ventral side of the fin, under the skin, but in the H olocep hales, where it has only been little
developed, limited to the appendix-shaft.

The skeleton of the appendage belongs always to the axial stem of the fin-skeleton 1 ); among
the rays (in the Plagiostomes, not in the Holocephales) only the hindmost, most frequently the
two hindmost, are of importance as serving as attachment for part of the appendix-muscles (those of
the glandular bag); as a consequence these rays have been somewhat bent, with the convexity turned
dorsally; the two hindmost are often partly, sometimes quite coalesced.

With the primary skeletal parts, developed from the fin-stem, join, in the Plagiostomes,
several very differently shaped, calcified, secondary skeletal pieces, developed in the connective tissue,
surrounding the original, primary skeleton. These secondary pieces show, especially in the terminal part,
a considerable variation, both as to form and number, and the different genera, or even species, may
present lather important differences; but everywhere may be established the same fundamental type
that has been pointed out in the Greenland Shark.

In the Plagiostomes the primary skeleton consists of: a large basale (j5), and in continua-
tion of this one or more (until a number of four, Rkinobatus) shorter pieces (b s , b 2 , etc.), and finally a
terminal joint, the appendix-stem [b); this latter is always long, often considerably longer than
the other parts of the stem taken together. To these pieces must be reckoned one more, /?, placed
dorsally, parallel to the short stem-pieces b T , b 2 etc. ; most frequently it connects the basale with the
appendix-stem, but sometimes it does not reach the basale anteriorly, and is then connected with b x \
in Rliiini it is rudimentary, and only connects the last joint with the appendix-stem; in Narcine it
seems to be wan tins:.

In quite young males of Plagiostomes (cp. fig. 2 in the text), even in embryos, all these primary
skeletal parts are already found; during the growth the terminal joint, the appendix-stem, is prolonged,
growing much more than the other parts, and calcifying to some degree in the surface (often to a
higher degree than any other part of the primary skeleton of the fin) always, however, with the
exception of the distal terminal part, this often wholly, and at all events at its base remaining
soft, and consequently flexible; this part of the appendix-stem I (after its form iu the Greenland Shark
and many other Sharks) name the end-style (g).

Contemporary with the growth and the calcification the secondary skeletal parts develop
around the appendix-stem, first as firm, fibrous parts, calcifying by degrees, and finally very hard;
some of them belonging to the terminal part are even shining, polished, and dentine-like; they then
rise, more or less naked, through the skin; this applies to one piece in Somniosus, Lannia, Selachus,
Rkinobatus, Raja radiata; to two pieces in Acanthias, three (four) in Spinax etc.

Two of the secondary skeletal parts are always closely connected with the appendix-stem, and
may even quite coalesce with it; these two cartilages form shorter or longer ridges, and are situated,
one dorsally, the other veutrally, connected with the appendix-stem in such a way as to form with it
the part of the appendix-slit that cannot be widened; they are the two marginal cartilages, the

') When A. Fritsch (Zool. Anzeiger, vol. 13. 1890, p. 318, and Fauna tier Gaskohle etc. Bohmens, vol.3. 1895)
restores the ventral appendages of the fossil Xeuacanths as lateral structures, developed from rays, I am convinced that
he is wrong, and 1ms misinterpreted the fossils.

ON THE APPENDICES GENITALES iCEASPERS) IN THE SELACHIANS.

r 9

dorsal one (Rd), and the ventral one (Rv); posteriorly they always reach to the end-style, anteriorly
more or less forward, commonly not to the same length, and at most to the proximal end of the
appendix-stem. Together with this they form the chief piece* of the appendix-skeleton, a name
used by several earlier authors, who most frequently have not seen that this piece consists of
three parts.

The other secondary cartilages, the terminal pieces, together with the end-style form the
skeleton of the terminal part, and are more or less movably connected mutually, with the marginal
cartilages, and with the end-style. The number of terminal pieces may be different, but in all Plagi-
ostomes two are found, one dorsal (Td), and one ventral (Tv), placed as a kind of movable continua-
tion of the two marginal cartilages, and with their inner edges joining the end-style of the axial
piece, which bv being bent (ventro-medially) is moved in connection with them; thereby they dorsally
withdraw more from each other, and the slit between them is widened. Only in a few cases (Trygon
violacea, Chlamydoselackus) these two pieces are found alone; in most Sharks a piece Td 2 is joined to
the lateral margin of Td, and imbedded together with
this in the dorsal lip of the appendix-slit; often a piece
Tv 2 is in a like manner joined to Tv\ further is gene-
rally found a piece T 3 , placed veutrally and laterally,
and often rising through the skin as a spur or thorn;
still more pieces may be developed (especially in Raja),
but their homologies in the different forms are gener-
ally easily pointed out, and are in the special part indi-
cated by the letters used. Finally may to the terminal
pieces proper be joined one or more « spurious- pieces
or covering pieces, enclosing like a shield the
terminal pieces, properly so called, on the dorsal side
(d) or the ventral side ('•); they are developed in the
aponeurosis of the 31. dilatator bespoken later on, which
otherwise wraps the terminal part, and serve as insertion
for part of this muscle. Such covering pieces are found
in all Rays and in some Sharks (for iust. Rhina). As
to the abundantly varied structure of the terminal part
the reader is referred to the special part; here I shall
only add that the simpler forms are generally found in
the Sharks, to which may be joined among the Rays
Torpedo, Narcinc, Rhinobatus and Trygon, while the
most complicated structures are found in the species
of Raja.

Perhaps it may not be devoid of interest to compare the ventral skeleton of the male with that
of the female. In this latter we find the stem composed of a large basale and a different number
of shorter joints, among which the terminal one has no ray (typically), but often looks like a ray

Kg- 3-

Fig. 2.

Fig. 2. Somniosus microcephalics, young o" (2 m 50cm).
The hindmost part of skeleton of left ventral (con-
siderably diminished). The letters as before. * an
intercalated extra-ray.

Fig. 3. Somn. microcephalus, 5. The corresponding
part of skeleton of left ventral, ij + b 2 two coalesced
stem-joints; the stippled line indicates the distinction,
found between these joints in the right ventral of the
same specimen, b the terminal joint. Reduction as
in fig. 2.

20 ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

itself being more or less rodshaped. This latter joint, I suppose, is the one that in the male is pro-
longed and developed into the appendix-stem, which never bears rays; otherwise, however, the number
of intermediate joints* between the basale and the terminal joint (the appendix-stem in the male)
does not always correspond in the two sexes of the same species, and the part of the stem situated
distally of the basale seems upon the whole to be rather varying in females of the same species 1 ). In
the female, as was to be expected, all the secondary skeletal pieces are wanting, but besides those
also the piece ft of the primary pieces. It is rather difficult to decide with any degree of certainty,
how this piece is to be interpreted; perhaps it might be done by following its development. The
smallest embryos (of Acanthias) that I have had occasion to examine, however, have had this piece
quite independent, in the same position, and with the same relations as in the grown animal. This
piece, however, has to be considered as belonging, either to the stem, or to the rays, and in the latter
case it is, I think, to be regarded as one ray, there never being any mark of a composition of more
jjarts. In several species, as Trygon, Rhinobatus, it might, as to its form, remind of a ray, which then
was to be considered as displaced to a higher level than the others, and turned parallel to the axial
stem; in Trygon it must be the last, hindmost ray, while in Rliinobatus it could not be the last ray,
as more real rays follow farther backward; and so on in the other species: if it was to be considered
as a ray, it must, in the different species, be a different ray, displaced and transformed. I think it
more probable that the piece j3 belongs to the stem, and has been separated from this by a longitu-
dinal division, which might possibly be occasioned by the development of special muscles for the
appendix.

In the Holocephales (see pi. I) all secondary cartilages are wanting in the fin-skeleton : it
is only composed of a large basale bearing all the rays, of a short piece b T , the appendix-stem b, and
the dorsal piece ft. The walls of the appendix-slit are produced by a kind of rolling-up of the stem-
portions bj, and b, and thus the terminal part is only formed of the hindmost part of the appendix-
stem; this latter is rather differently formed in the two genera Chu/iirra and Callorhynchus (see the
special part).

The appendix-skeleton of the Holocephales accordingly is of a less compound construction
than that of the Plagiostomes, and that, as will be seen hereafter, is also the case with the muscular
system. This simpler structure evidently in some degree repeats primitive features, but these, on the
other hand, are connected with facts, that by no means are primitive, as for inst. the strongly marked
separation of the whole organ from the fin proper, the highly specialized form of the primary skeletal parts
- against the simpler form in the Plagiostomes (as the simple, rod-like shape of the terminal joint b etc.) — ,
the connection with other, particular copulatory organs, etc.; these things, as well as many other facts

') In two specimens of ventrals of female Greenland Sharks I find the structure different in the two sides of the
same pair of fins. In the left ventral of one specimen the basale is followed by a long and powerful joint, (A1 + &2, fig- 3)
bearing two rays, and a ray-like little terminal joint i; in the right fin of the same specimen follow after the basale two
short joints 'the- distinction between those is indicated by stippling in fig. 31 61, 62, each bearing one ray, and i 2 also the
little ray-like terminal joint i; thus on the left side a coalescing of it and i 2 seems to have taken place. On the left side of
the other specimen follows after the basale only one sword-like, compressed piece, taking the place as the terminal joint, and
showing in its distal end, which is somewhat flattened, an indication of a longitudinal division; in the right side, on the
contrary, the basale is followed by a short joint (6i) bearing a ray and a compressed terminal joint ii). Consequently, if we
suppose a coalescing of it and & on the right side, together with the last ray, we shall arrive at the structure on the left
side. As far as I have seen, the female fin-skeleton of Acanthias shows similar variations.

ON THE APPENDICES GENITALES (CLASPERS) IN THE .SELACHIANS. 2 I

in the structure of these animals indicate that the Holacephales by no means occupy a primitive
position among the Selachians.

As to the skeleton of the ventral in the female, the basale (in Chimera) has distally only one
small, tap-like joint, standing both for the piece b T , and the appendix-stem (b) in the male 1 ).

What has been given in the earlier literature as to the skeleton of the ventral appendages in
Selachians, is generally only isolated descriptions without any real understanding; only Gegenbaur 2 )
and Petri have compared several forms, but neither of them has been able to recognise a
common type. Gegenbaur (1. c. p. 452) has interpreted the terminal pieces as modified rays, but on
account of the circumstances in the Cliimccra, he indicates (p. 456) the possibility that they may be
parts separated from the stem-skeleton ; he does not know the marginal cartilages, and he has considered
several early stages of the skeleton as definitive forms of it. Petri cpiite correctly has seen that
the terminal pieces and marginal cartilages - - which latter, however, he has not recognised in all
the species he has examined -- are secondary structures, and have nothing to do with the rays; the
terminal stem-joint itself which I have called the appendix-stem (/;), he has interpreted correctly in
Raja, but wrongly in Acanthias and Scyllium*) --- the only Sharks examined by him -- as well as in
Torpedo -t) (he has not examined Chimara). Some earlier authors have seen the piece ft in some
specimens, while it by others has been overlooked, or at all events has not been mentioned. Only
Gegenbaur and Petri have sought its origin in a transformation of other skeletal parts of the
fin?). Gegenbaur does not mention it at all in Raja, Carcharias and Scylliuiu 6 ) but in Hctcrodontus
and Acanthias (I.e. fig. 16 and fig. 19,/'), and in Chimmra (fig. 23 r'); in the last named it is interpreted
as a ray, but in the two former as belonging to the stem-skeleton?); accordingly Gegenbaur has not
seen that in Chimccra it is the same skeletal piece as in the Plagiostomes. Petri thinks it to be a
coalescence of basal parts of rays, being of opinion that it bears rays in Acanthias and Torpedo;
accordingly in his figures he marks it /. This supposition, however, is wrong 8 ); I never found rays

1 v. Davidoff (I.e. p. 473, pi. XXIX. fig. lS<$) thinks it only to be corresponding to <5i. Unfortunately I have only
had occasion to examine skeletonized ventrals of Chimara 9, in which this joint was wanting, so that the fin-stem consisted
only of the basale.

2) Ueber die Modificationeu des Skelets der Hintergliedmaassen bei den Mannchen der Selachier und Chimiiren. Jen.
Zeitschr. vol. 5, 1S70, p. 452.

3) In these Sharks Petri supposes the stem to end with a long and a short joint; in Acanthias as the short terminal
joint he has interpreted one of the terminal pieces (my piece Tv), in Scyllinm the soft end-style.

4) As to Torpedo see p. 49.

5) Bloch, M. E. : Von den vermeinten doppelten Zeugungsgliederu der Rocheu und Haye. Schr. der Berl. Gesell-
schaft Naturf. Freunde, vol.6, 17S5 [Raja clavata ■ [= radiata]) ; and: Von den verm, mannlichen Gliedern des Dornhayes,
ibid. vol. 8, 1788, does not mention this piece in Acanthias, but in Raja, where he calls it: .der vierte Knochen des Schenkels »,
pi. IX, fig. 1,0. Cuvier (Duvernoy): Lecons d'anatomie comparee, 2 Ed., 1846, vol 8, p. 306, designates it as Calcaueum
in Raja; the same appellation is used, likewise for Raja, by Moreau: Hist. nat. des Poissons de la France, vol.1, 18S1,
p. 249. I have not found it mentioned by other authors.

*>j Of these three forms G. has only had quite young specimens, in which the secondary pieces had not yet devel-
oped. The fault made here by G. viz. to consider this stage as the full-grown state, and accordingly as an especially simple
form in these Plagiostomes. has already been corrected by Petri (I.e. p. 293). It is to be supposed, however, that the piece
,j had been developed in all three forms, as in embryos of Acanthias of a length of only 15cm it is already quite distinct and
relatively as large as in the full-grown animal.

7) I am quite unable to understand the place in question (1. c. p. 45 1) in Gegenbaur; there is a regrettable discre-
pancy between the letters in the text, and those in the figures, and also, I think, a change of pieces, which makes the whole
confused; so much, however, is certain that the piece which in the figures 16 and 19 is marked b (my piece /S) does not in
Acanthias bear any ray; it never bears rays at all.

8) For further details see under Acanthias and Torpedo. When Petri, to support his construction of this piece as

22 ON THE APPENDICES GENITALES 1CLASPERS1 IN THE SELACHIANS.

attached to this piece, but always found it placed at another level than that of the nearest rays, and
I take it to he a specially separated part of the stem-skeleton.

The muscular system (see pi. V and VI) does not show the rich variation found in the
skeleton, being upon the whole rather uniform, which is a natural consequence of the fact that the
part of the skeleton, particularly multifarious both as to the number and form of the single pieces,
viz. the terminal part, has no muscles of its own; the muscles (generally) only acting on the terminal
part as a whole.

Only the medial side of the fin-muscles has been specially developed in the male; the muscles
spreading over the lateral parts of the fin, i. e. the ray-muscles of the upper and lower side, and the
dorsal layer originating from the lateral muscles of the bodv, are chieflv the same in both sexes,
and show in the different forms examined so very few differences that I, also in the special part, pass
over them.

In the medial muscular system may be distinguished between a more proximal and a distal
part, not however strongly separated, especially not so in many Plagiostomes , while in the Holoce-
phales the separation is more distinct, the appendage of the latter being more independent of the fin.

In the Plagiostomes I generally find the same type, as has been described in the Greenland
Shark. The proximal part consists of a Muse, adductor [et depressor) piuiicc (or appendicis) [A), and a
J/, extensor appendicis (E). Muse, adductor does not in any of the forms examined by me show any
separation into an independent, superficial ventral layer, and a deeper, more dorsal one, but forms a
whole 1 ); the ventral side, however, appears to a great extent separated into single bundles correspon-
ding to the ray-museles, while the dorsal side shows nothing of the kind. The fibres arise from the
pelvis, as well from the ventral, as, though often to a smaller extent, from the dorsal surface, as also
from a tendinous stripe prolonging, as it were, the hindmost edge of the pelvis into the median line;
they run oblicpiely-laterally , and are inserted on the basale, on the following joints (b M b 2 etc.), and on
the proximal end of the appendix-stem; often, however, the superficial medial fibres run on and mingle
with the M. dilatator. The fibres forming the medial marginal part, run almost straight from before
backward, and form always a solid mass not divided into separate bundles; the foremost, lateral parts
(as in the Greenland Shark) are coalesced with the deeper-lying ray-muscles.

M. extensor (appendicis) (E) is mostly a rather flat muscle, situated on the dorsal side of the
previous one; it originates on the medial side of the basale, often moreover on the pieces 6 1} b 2 , etc.,
and is inserted on the appendix-stem, usually at the proximal end, but sometimes farther backward,
and the hindmost part of this muscle then spreads in a cloak-like manner over part of M. dilatator
(comp. the Greenland Shark). This muscle generally is very distinct, already in quite young animals
with undeveloped appendages; but in Lanuia I find its fibres woven into those of 2f. adductor to

a coalescing of basal parts of rays, refers to the fact that such a coalescing of rays is frequently seen in other parts of the
fin, especially anteriorly, he does not see that the basal joints of the rays always are many times longer than the distal, and
that this difference of size is also preserved by such concrescences.

'! The type of the arrangement of the ventral muscular system put down by v. D avidoff (1. c. p. 4561 for Heptanchus
9, which reminds of the arrangement in Chimara, I have had no occasion to see in any Plagiostome; v. D. asserts to have
l " 1 "" 1 '< very generally, and refers to Acanthias almost as an exception; however, I can with certainty see no other forms
mentioned in his text than Carcharias as belonging to the same type as Heplanclms.

ON THE APPENDICES GENITADES (CLASPERS) IN THE SELACHIANS. 23

such a degree that it does not appear as an independent muscle, and only artificially is to be separ-
ated from the former.

The distal part, the muscular system of the shaft, is typically composed of two muscles: M.
dilatator (/)), and M. compressor (saccz) (S).

M. dilatator [/>) is always very large and powerful; it wraps in a cloak-like manner the appen-
dix-stem until the terminal part, leaving only the lateral surface uncovered, part of which is occupied
by M. compressor. M. dilatator originates forward, either from the appendix-stem only, or frequently
also, above the knee of this latter, from the pieces 6 l} etc., or from the basale; posteriorly it is
attached to the aponeurotic wrapping of the terminal part, or, when covering pieces have been devel-
oped from the wrapping, partly to these. Besides fibres of it often go to the skin, and here and there
bundles pass into the M. compressor. The chief action of this muscle is to bend the terminal pieces
together with the soft end-style (veutro-) medially, by which means the terminal part of the appendix-
slit is widened; at the same time some of the terminal pieces are often turned from their position
of rest in such a manner that they rise through the skin, or are erected so that they stand out free
(as the spur or thorn in Sonmiosiis and Lauiua, the -claws in Spinax, the hook and the spur in
Acanthias; the large piece T^ in Ra/a, etc.). When the contraction ceases the appendix-slit will again
be narrowed, and the erected skeletal pieces will again be laid, partly mechanically by elastic
reaction of the soft connective tissue, but partly also the M. compressor will be able to support this
latter operation.

Muse, compressor shows in the Plagiostomes so particular a structure, that when it has been
examined at all, it has hitherto been misapprehended, the greater part of it being understood as a
bag composed of dermal muscles.

This muscle, I suppose, originally occupies in the Plagiostomes a place, similar to that in the
Holocephales (see later); i.e. it covers the lateral surface of the appendix-stem, or very frequently
only its proximal part, and anteriorly it also reaches on to the piece t 3 and the (two) last rays. Into
this muscle, a longitudinal folding of the outer skin penetrates from the dorsal side of the shaft; this
folding forms the appendix-slit and the glandular bag, the former leading into the latter. The fore-
most part of the folding growing on ventrally, carries with it the wrapping muscle, and then both
grow on together, and form a singularly thickwalled bag which from the slit-formed opening on the
dorsal side grows 011 between the last ray and the stem skeleton to the ventral side of the fin, where
it becomes situated between the outer skin and the ventral ray-muscles. In Sharks the foremost,
blind part very often grows much farther forward, not only near to the pelvis, (Spinax, Rhiua,
Somniosas) but in many, I think in most Sharks it reaches forward of the pelvis (for inst. Acanthias,
Scyllium, Pristiurus, Laiiuia, Selae//us)'), and then the bags of the two sides are in contact a long
way in the median line (fig. 4). In the Rays the bag is much smaller, (pi. VI, fig. 68), but on the other

M In Mustehis /avis the glandular bag reaches as far forward as to the pectorals; i. e. the part before the pelvis is
of far more the double length of that behind it. I have myself only had immature males of Must, tavis for examination ;
but this statement I found on a drawing without any text, left by A. Schneider which, together with other drawings, has
been published as an appendix to the fragment left by S. : Studien zur Systematik und zur vergl. Auat., Eutwickelungsge-
schichte und Histologic der Wirbelthiere 1Z00I. Beitrage, vol. 2, 1890). The figure in question (pi. 25, fig. 11) is explained as:
Mustelus l&vis. Brustflossen und Bauchflossen mit Saamenblasen. Die Cutis entfernt. Bauchseiu-.

24

ON THE APPENDICES GENITALES iCLASPERS) IN THE SELACHIANS.

hand its secreting part is especially developed, and its muscular wall somewhat more complicated.
In the part of the M. compressor forming the muscular wall of the bag, the direction of the fibres
may be rather different, but they chiefly radiate in bent lines towards the periphery, or round this

to the dorsal surface; this latter is only by loose connective tissue
connected with the ray-muscles. In the part in the shaft the
direction is more straight, parallel to the axis; this is the case
with the fibres covering the lateral surface of the appendix-stem
(or a short proximal part of it), as also with those forming the
outer, lateral border of the appendix-slit. This lateral part most
frequently appears on the dorsal side as an independent muscle,
and might be called the outer lip-muscle , being, as it were,
separated from the other part of the wall of the bag by the at-
tachment of the fin-membrane. By a closer examination and by
a transverse section through this region (cp. fig. i and 14 in the
text) I have been convinced of its forming a whole with the other
parts of the muscular wall of the bag, with which also the corre-
sponding part in the Holocephales forms a complete union (see
later). A large part of this outer lip-musele» originates anterior-
ly from the piece /9 and the hindmost ray, or rays; posteriorly it
is inserted partly on the inner investment of the ventral marginal
cartilage, partly on the aponeurotic covering of the ventral termi-
nal pieces, and acts through this especially on the piece Tv. The
muscular coat formed by M. compressor will by contracting expel
the fluid secreted from the epithelium of the bag; but besides its
hindmost, lateral part, the outer lip-muscle , when it is long and
powerfully developed (as in Sharks with a short ventral marginal
cartilage, for inst Somniosus, Spinax , Acanthias, R/uiia), will
act antagonistically to M. dilatator, i.e. narrow the dilated terminal part, and lay the erected ter-
minal pieces.

The muscular system of the appendix which here has been briefly represented in its typical
characteristics, shows in different Plagiostomes special modifications, as to which the reader is referred
to the special part I shall only here state that the part of M. compressor which appears as the outer
lip-muscle of the appendix-slit, commonly, as to its size and development, is adjusted to the length
of the ventral marginal cartilage; therefore it is very small in Scyllium (pi. VI, fig. 66, S), and in
1'ristiurtts, rather small in Raja (fig. 67, S); longer and more powerful in Torpedo, but especially de-
veloped in Sharks as Sommosus, Acanthias, Spinax, Rliina , a. o. From the part of M. compressor
wrapping the bag proper, is in the Rays developed a special muscular layer around the voluminous
gland found in these latter. In the Sharks (with the exception of Rkina) the inner epithelium of the
bag does not form real glands, but only contains secreting cells, and is accordingly very simple as
secreting apparatus. In the Rays, however, has been developed a bulky gland protruding as a

Fig. 4.

Acanthias vulgaris rj. The ventrals
seen from the lower surface. 5 M. com-
pressor, A M. adductor , D M. dila-
tator, R ray-muscles, T$ the < spur .
The stippled contour indicates the an-
terior extent in another specimen.

ON THE APPENDICES GENITALES (CLASPERS) IX THE SELACHIANS. 25

thick, oval body from the dorsal wall of the bag into its inner space, and almost filling it; when the
ventral wall of the bag is opened, this body is immediately seen, and in sound animals it is sometimes
seen rather distinctly through the skin 1 )- Down the middle of the gland rnns straight or obliquely
(Trygon) a longitudinal furrow, in which is seen a great number of rather large holes with raised
margins: they are the excretory openings of collective dncts from a solid mass of large, dichotomously
divided, tubular glands. This gland is on all sides until the longitudinal furrow enclosed by a mus-
cular layer, originating from the dorsal muscular wall of the bag. By this special muscular layer the
secretion may evidently be ejected into the inner space of the bag, and then by contracting of the
muscular wall of the bag itself be driven on, partly through the large opening at the base of the
shaft, partly posteriorly through the tube , formed by the marginal cartilages, and 011 through the
terminal part; in full-grown animals these latter ducts are generally found filled with the secretion.
Among the Sharks I have only in Rhina found a similar bulky gland, but situated only in the shaft
(for further particulars see under Rhina).

A survey of the medial fin-muscles in the females of the Plagiostomes will show that they
are of a considerably simpler structure than those of the male. In the female is found only one single
muscle, a M. adductor pinna (pi. V, fig. 63, 64, A) originating in quite the same way as in the male
from the pelvis and its aponeurotic prolongation in the ventral median line, and built in a similar
manner as to the division of the ventral side in separate bundles, the passing of the foremost lateral
part into the ray- muscles, a. s. o. ; here , too , the medial marginal portion forms a solid mass, continu-
ing as a posteriorly tapering bundle on to the terminal joint of the fin-stem 2 ).

It is then -- especially considering the intermingling of fibres that often takes place in the
different muscles of the male -- an obvious conclusion that an adductor of a similar simple construc-
tion as the one, now found in the female, has been the origin of the J/, adductor, the J/, extensor,
and the M. dilatator, perhaps also of the J/, compressor of the male. When the hindmost joint of the
fin-stem developed into the appendix-stem, the distal part of the orginal, simple M. adductor might
be thought to be brought along at the same time, so that part of the deeper-lying fibres would origin-
ate from the stem-skeleton, by which process the J/, dilatator would arise; while in the proximal
part too a group of fibres originating from the stem separated as the M. extensor (in Lainua this
muscle is only part of the M. adductor). The .1/. compressor might have the same origin as the J/
dilatator, but more likely it represents the very hindmost ray-muscles.

In the males of the Holocephales ipl. VI, fig. 69 — 71) the separation between a proximal
muscular group and a distal one, placed on the appendix-shaft, is, as before mentioned, more strongly
marked than in the Plagiostomes. The proximal group is formed by a M. adductor, corresponding
to that of the latter, as to the detailed structure of which I refer to the special part; a separate M.
extensor is not found. The distal part is also here composed of a M. dilatator and a M. compressor,

1 This gland was already seen long ago. J. Th. K 1 e i n ( Historise piscium naturalis promovendae missus tertius etc. cum
observationibus circa genitales Raja? maris etc. 1742), as far as I have seen, is the first author, who mentions it. He thinks
the gland to be a kind of testis (forte officina seminis |, but observes that he has not been able to find any connections
with the kidneys, nor with vesiculis seminalibus — adesse tamen possunt >. E. Olafsen in his Icelandic voyage (II p. 9S8)
takes the same view of the gland as Klein.

2 ) The figure of Acanihias J given bv v. Da vidoff, 1. c. pi. XXIX, fig. 12, is not correct with regard to the direction
of the fibres; so I have given a new figure.

The Ingolf-Expedition. II. 2, 4

OX THE APPENDICES GENITALES CLASPERS) IN THE SELACHIANS.

the latter being of special interest with regard to a comparison with the Plagiostomes; it is much
thicker than the M. dilatator, and covers the lateral surface of the stem-piece b z , and of the piece b
to the terminal part. Into this mnscle sinks through the dorsal appendix-slit a continuation of the
outer skin as a « glandular-bag , which on account of its simplicity might be called rudimentary ,
when compared to that of the Plagiostomes, as it has evidently remained in a similar stage of
development as that, with which it begins in those; by a further development forward and ven-
trally a quite similar glandular bag would arise as the one described as characteristic in the Pla-
giostomes. The direction of the fibres of the M. compressor is rather peculiar in the Holocephales
(see the special part); here I shall only mention that part of the fibres seen dorsally (fig. 70), runs along
the lateral edge of the appendix-slit rather straight from the piece [i backward in quite the same
manner as in the corresponding part, the outer lip-muscle , of the M. compressor in the Plagiostomes.
The wdiole structure of this muscle forms, as it seems to me, an incontestable proof as to the correct-
ness of my interpreting the muscular coat of the glandular bag of the Plagiostomes as part of the
skeletal muscles proper.

In the female the whole muscular system of the appendix is wanting; according to v. Da-
vidoff the little terminal joint has an attachment for part of the dorsal muscles arising from the
wall of the body (1. c. p. 477, pi. XXIX, fig. 18, ps), corresponding to the attachment of the same muscle
on the piece b z in the male; just on account of this v. Da vidoff exjulains the terminal joint to be
homologous with this piece.

The fin-muscles of the male have been rather slightly treated in the earlier literature; a com-
parison between several forms has been almost quite out of the question, only a few forms having been
described. Thus among the Sharks Acantliias has already been mentioned by Bloch, among the
Rays some Raja- species by several authors (Raja radiata very briefly and incompletely by Bloch,
Raja circ n ton's [or elavata\ by Duvernoy, R. elavata by Vogt &: Pappenheim and later by
Moreau), Chimara monstrosa by v. Davidoff. Petri alone has examined several different forms
and tried to make a comparison, but he cannot be said always to have been successful or to have
found the correct interpretation. While he upon the whole pretty correctly has interpreted the muscle
I have called M. adductor, -- his M. flexor pinna, or pterygopodii, a name rejected by me as presum-
ably not suitable, -- and M. dilatator, a name introduced by him (at all events in Scyllium, Acanthias
and Torpedo), the other muscles have either been misapprehended or not at all mentioned. The M. extensor
he has only seen in Scyllium and Raja, where he calls it M. flexor pterygopodii inferior, and of my
J/, compressor he has only mentioned the part, which I have called the v outer lip-muscle » (of the
appendix-slit), in Acanthias and Raja, and with different appellations, respectively as M. levator (of the
spur) and as M. flexor biceps (which latter name is also given to a quite different muscle in Scyllium),
and he has assigned to it different, partly misapprehended, functions. It has already been observed
that both Petri and all other authors, who have mentioned the glandular bag, have understood the
muscular wall to be a separately developed dermal muscular system, and consequently omit it by the
mentioning of the fin-muscles proper. In the special part account will be rendered of the earlier
literature, and the particular works will be referred to.

ON THE APPENDICES GENITA] BS (CLASPERS) IN THE SELACHIANS.

27

2. Special Part.

Selachoidei.
Spinacidce.

Acanthias vulgaris Risso.

(PI. I, fig. 10, 11.)

The common picked Dog-fish has been so often examined that I think a more particular de-
scription of the external features of the copulatory appendages to be superfluous; I may refer to
Petri 1 ) (with regard to whose description, however, I must remark that the investment with dermal
teeth at the places of transition to naked parts does not cease gradually, but is quite sharply bounded;
the dorsal side is wholly naked, as is also on the ventral side the hindmost point of the terminal part),
as also to the earlier description by Bloch 2 ) and Homesj. In a specimen of the length of 64 cm the
following measures were found:

Length of the appendix (from the fore-edge of the cloaca) . . 6,5 cm

part free of the fin 3) icm

terminal part 2, 2Cm

appendix-slit 4i 2Cm

Breadth of the appendix ab. i cm

The skeleton has not been cpiite correctly described by any of the earlier authors + ).

Between the basale and the appendix is found only one short joint ($,), and besides the dorsal
piece /??); this latter articulates anteriorly with the basale, posteriorly with the appendix-stem b, and
medially with b t ; its lateral edge is convex, projecting somehwat in the shape of a roof over the two
hindmost rays ; these rays are borne by the piece b l , and are often coalesced ; they are stronger and
longer than the last ray but two, which latter comes from the basale.

The stem of the chief piece of the appendix has a length like B -\- b z , and proximally towards
its articulation with b 1 is found a ridge (at b in fig. 10) projecting in a somewhat keel-like manner;
in the hindmost half it has laterally a little trough-like hollow. The soft end-style is short 6 ), flatly
rounded, and reaches not nearly to the end of the terminal part. The dorsal marginal cartilage?)
(Rd) can forward be indistinctly traced as a rounded ridge to about the letter x in fig. 11 (it is more

-I I.e. p. 300, pi. XVII. fig. 5, A.
'-\ 1. c. 178S, p. 9, pi. 2, fig. 1.

3) On the Mode of breeding of the Ovoviviparous Shark etc. Phil. Trans. 1810, Pt. II, p. 205, pi. IX and X; in the
lastmentioned place the ventrals ami the appendages have been drawn in a position, which they scarcely naturally would
be able to have.

4) Drawings are found not only in Bloch. Gegenbaur and Petri, but also in Molin: Sullo scheletro degli
Squali. pi. Ill, fig. 7; Memorie dell' 1st. Veneto, vol.8, 1859, but without any explanation or description in the text.

= i Gegenbaur, fig. 16, b\ Petri, fig. 5 D, >■'.

•' Gegenbaur, fig. 17, /; it has been quite overlooked by Bloch and Petri.
1 Men tinned neither by Gegenbaur nor Petri. The hindmost end of it is the Processus a am Schienbein»
0- c. fig. 31 of Bloch. Neither of these authors have seen independent marginal cartilages in Acanthias.

\

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

distinct, when the piece is dried); posteriori}- it is distinctly elevated as an edge of the appendix-slit.
The ventral marginal cartilage {Rt>) is shorter, resembles the corresponding one in the Greenland
Shark, and has, as in the latter, a plate-like part 1 ) folded to the dorsal side; on the concave inner
side it has furthermore a strong, elevated process; in the furrow between this process and the folded
part the proximal end of the thorn is placed.

There are four terminal pieces.

Td 2 ) is narrow, with the foremost part of its medial edge closely connected with the end-style,
and behind this with the edge of the ventral piece Tv; distally it takes the form of a flattened, sharp-
edged hook; this hook-shaped part rises uncovered through the skin, is smooth, shining, and dentine-
like. Td is with part of its lateral edge connected with a quite thin, plate-formed piece 3), Td 2 , also
anteriorly connected with the marginal cartilage Rd; it is placed in the skin forming the dorsal lip
of the appendix-slit of the terminal part, and corresponds to the piece Td,, indicated in the Green-
land Shark.

The ventral terminal piece, Tv4), is considerably broader and longer than the dorsal one,
rounded on the ventral (outer) surface, hollowed like a spoon towards the appendix-slit; except the
hindmost ]3art it is firmly calcified; the foremost part of the medial edge is connected with the end-
style, and behind this with Td, the hook of the latter lying freely in the outermost spoon-like end of
the former piece; in the proximal end it has medially an articular process for articulation with the
above mentioned process of the concave side of the marginal cartilage Rr, and its lateral edge is
firmly connected with a strong, thin membrane (fig. n, Tv 2 ), serving in the foremost part for attaching
the outer lip-muscle of the glandular bag; this membrane then corresponds to the similar, but thicker
one in the Greenland Shark, and to the piece Tv 2 in Sjhinax.

The fourth terminal piece, T 3 , is the one called the < spur» 5) by the different authors; with the
proximal, somewhat head-shaped end it is attached inside of the folded plate of the marginal cartilage
Rv to the above mentioned process, and to the proximal and lateral end of the piece Tv; it is formed
as a triangular thorn or spine, longitudinally somewhat twisted, with two concave surfaces; it is firm,
shining, dentine-like, and the greater part of it is uncovered by the skin. It can be moved quite in
the same manner as the corresponding spine in the Greenland Shark.

The muscular system. The M. adductor shows the general typical relations. The M. extensor
reminds very much of the same one in the Greenland Shark; as in the latter it has here its origin
on the medial side of the basale and b u stretches over the «knee of the appendix-stem as a thin,
flat covering over the M. dilatator, and inserts itself along the boundary line of the dorsal marginal
cartilage.

The M. dilatator originates proximally with a dorsal portion at the same place as the M. extensor
and quite covered by it, that is to say some way up on the basale; on the ventral side its proxi-

n Bloch, Processus d\ Gegenbaur, fig. 15. 16, a; Petri, fig. 5, D, E, pr\ regarded by all only as a process 011
the chief piece.

1 Bloch, der Haken, fig. 2, c, fig. 6; Gegenbaur fig. 16, 17. a; Petri, fig. 5. hk.
)) Petri, fig. 5, la; it is neither mentioned nor drawn by Bloch or Gegenbaur.

4) Bloch: der breite Knochen, fig. 2, d, fig. 5; Gegenbaur, fig. 15 — 17, c; Petri, fig. 5. &"', he interpreting it as
tlu- terminal joint of the stem.

Bloch, der Sporn, fig. 2, c, fig.4; Gegenbaur, fig. 15, 16, a'; Petri, fig. 5, sp and ca.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 29

mal origin accordingly is much more backward, at the distal end of the M. adductor; it is inserted as
usual, its aponeurosis being especially attached to Tv and Td\ the latter piece, .the hook , is turned
(round its medial edge as the axis) out of its position in the spoon-shaped end of the former, when
the muscle is contracted during the dilation.

The part of the M. compressor wrapping the bag, is much distended, and consequently rather thin,
corresponding to the considerable extent of the bag anteriorly (see fig. 4 in the text). The part inserted
on the lateral surface of the appendix-stem, is very small, reduced to a few bundles of fibres on the
proximal end of this part of the skeleton, which otherwise is almost quite enclosed by the M. dilatator.
The part, which as outer lip-muscle forms the lateral limit of the appendix-slit, seems to me to
receive in its surface some fibres coming from the muscular layer originating from the lateral muscles
of the bodv, but otherwise it originates as usual on the hindmost rays and on /?; it is inserted with
a kind of tendon in the above-mentioned membrane on Tz>, and consequently it acts antagonistically
against the M. dilatator, and at the same time lays the spur 7\ ' 1.

Spinax niger Bonap.
(PI. I, fig. 12, 13.)

The very peculiar-looking appendages in this common Shark have singularly enough been
very little mentioned by earlier authors, and by many, also among the later, they are not mentioned
at all. Gunnerus 2 ), in his description of the «Sort-Haa», says: -they (i.e. the two Membra genitalia)
were supplied with some sharp bony spines, such as 1 have seen on the Membra of several Rays,
when the ends have been turned inside out. KroyerS) says: «At the end of the copulatory appen-
dages of the males are found three crooked thorns or horny claws, and a tapering dermal flap, which
behind projects a little over these claws. The claws are movable against each other, and form a kind
of prehensile organ. In the position of rest they are hidden between a pair of small cartilaginous
plates, and the skin covering these plates. » This is the most complete, and also, I think, the most
correct description I have seen-*). Dumerils) gives a drawing of the appendix, but with no explana-
tion whatever (nor in the text neither); the drawing is rather difficult to understand, neither is it
correct; thus the dermal flap mentioned by Kroyer appears in this figure as a thorn, although it is

■l Petri (I.e.) designates this part of 1113- M. compressor as M. levator (fig- 5. ml), and attributes to it a dilating
effect, having < allein die Aufgabe diesen (den Sporn) zu heben , and thus he in this place speaks of two dilating muscles.
The incorrectness of this, however, is easily pointed out. Contrary to Petri, Bloeh upon the whole has a correct understanding
of the mobilitv of the spur, speaking (1. c. p. 131 of eiuen sehr sonderbaren Mechanismus. Davon mir wenigstens in der
Anatomie kein ahnlicher bekandt ist . Bloch has a chiefly correct description of the muscular system; he distinguishes between
three muscular portions, the first of which being the ventral ray-muscles , the second, which he compares to the < adductor
femoris in man, is my M. adductor, the third M. dilatator + my M. extensor. He describes the glandular bag as a parti-
cular organ, to which he does not ascribe any muscular walls , as he supposes that the other 1 2 1 muscles expel its klebrigte
Feuchtigkeit . Neither has Petri seen my M. extensor as a separate muscle in Acanthias (see his fig. 5, B, and the descrip-
tion p. 3021; but it is also to be acknowledged that in this species it is very closely connected with the M. dilatator, especially
proximallv.

2 ) Throudhjemske Selskabs Skrifter II, 1763, p. 319.

3) Danmarks Fiske vol.111, 1S52 — 53, p. 908.

■ 1 Miiller & Henle, System. Beschr. der Plagiostomeu, 1S41, p. S6, say: <Kein Dorn an den mannlichen Anhangen ;
founded, I suppose, on young specimens, in which only the soft dermal flap is seen.
5) Hist. nat. des Poissons, vol. I, 1S65, the atlas, pi. IV, fig. 13.

3°

ON THE APPENDICES GENTTALES (CLASPERS) IN THE SELACHIANS.

U

Fig. 6.

quite soft. L,illj eborg 1 ) only says: The copulatory organs of the male are small and pointed, and
reach only a little behind the ends of the ventrals; they are until towards the end coalesced with the

ventrals.> As no thorns are mentioned, L. must have examined only undeveloped appendages.

The appendix, when fully developed, is
short, clumsy, thick, and reaches only a very little
farther backward than the end of the fin-membrane,
the free part of which is also very short. Dermal
teeth are not found, neither on the dorsal, on the
medial, nor on the greater part of the ventral side,
except on this latter laterally, near the fin-mem-
brane. In the numerous, developed appendices,
examined by me, the terminal part was always
very much dilated, and such was also the case in
the specimens, I have caught alive; in the dilated
state the terminal part stands almost at a right
angle to the stem, its hinder end with the soft
dermal flap (a) pointing inward towards the middle
line; the dilated part of the furrow then looks
like a concave sole of the foot, in whose &heel»
is seen the opening, through which the secretion
of the glandular bag is probably ejected. Three

polished, hard points protrude like claws through the skin, one at the dorsal lip of the furrow, the

second at the ventral lip, and the third, and longest, juts out, ventrally and laterally, from the spot,

where the fin-membrane becomes free of the appendix.

In specimens of the length of 35,5 c:n — 38,5 c,n the following measures are found 2 ).

Length of appendix (from the fore edge of the cloaca) . . abt. 2,5 cm — 3S cm

- the part, free of the fin

- the terminal part

- the appendix-slit

Breadth of the appendix - o,6 cm — o,S cm

The skeleton. Between the basale and the appendix are found two small pieces (b l and b 2 ),
each bearing one of the two hindmost rays (accordingly b 1 -\- b z in Sfinax = b Y in Acanthias); never-
theless these rays may be found coalesced, and are, as usually, directed straight backward, parallel to
the appendix. The piece /} is relatively somewhat longer than in Acautliias, but of a similar form.

The axial part of the chief piece of the appendix is somewhat more clumsy than in Acauthias,
but otherwise of a similar form, and also supplied with a short, soft end-style; including this latter
the stem is only a little longer than the basale. The marginal cartilages, too, show chiefly the same
relations as in Acanthias.

M Sveriges och Norges Fiskar, vol.3, 1S91. P- 677-

-1 It is somewhat difficult to obtain exact measurings on account of the terminal part being bent.

Fig- 5-

Fig. 5. Spinax niger. The appendage of the right side
with part of the fin-membrane, seen from the dorsal side,
somewhat enlarged. The terminal part is dilated, f the
folded , free end of the fin-membrane ; at the fin has
been cut from the body. afi the dilated part of the
appendix-slit.

Fig. 6. The dilated terminal part, seen from behind, a
the soft terminal flap, af the spot where the appendix-
slit passes into the dilated, terminal part of the furrow.

I)2 c.n
-rem

1,8""

0,6 cm -

ON THE APPENDICES GENITALIS (CLASPERS) IN THE SELACHIANS. 31

The terminal pieces are 5.

The dorsal one, Td, is somewhat s-shaped, round, and articulates medially with the end-style,
while the hindmost part of it projects through the skin as a curved, polished claw; as in Acanthias,
it is united with a thin lamellar piece, Td 2 , which piece, with the exception of the hindmost point, is
qnite covered by the skin forming the dorsal lip of the furrow.

The ventral piece Tv is also somewhat s-shaped, broader than the dorsal one, thick at the
base, becoming thinner distally and laterally; it is concave like a spoon on the side towards the
furrow, on the other side rounded. At the proximal part of the lateral edge it is firmly united with
a hard, dentine-like piece 7r' 2 , which in Acanthias is only represented by an uncalcified mem-
brane. This piece is before (proximally) prolonged to a long, flat end, behind (distally) to a shorter
one, projecting through the skin as the before mentioned claw in the ventral lip of the furrow; the
piece is rather narrow, ventrally concave, dorsally rounded. In moving it follows the piece Tv.

The last piece T 3 corresponds to the thorn, in Acanthias and Somniosus , and is also here
formed as an elegant, bent, rounded and completely smooth thorn with the proximal end head-shaped.

It is quite out of the question that these «claws», as supposed by K rover, should be able to
act as a prehensile organ , as they cannot properly be moved against each other; but they will be
very able to fix the appendix firmly in a hollow, as by the dilatation of the terminal part their points
are turned in three opposite directions, as may be seen from fig. 6 in the text

The muscular system. From the 31. adductor has been separated a long, flat bundle as a
particular muscle originating before from the medial aponeurotic stripe together with the other
fibres of the 31. adductor, and then on the dorsal side passing obliquely over the 31. extensor and
next over the M. dilatator; on the appendix it follows the appendix-slit, and forms together with the
31. dilatator the medial lip of this slit; partly it is attached in the skin of this lip, but chiefly on the
proximal end of the piece Td,. This muscle evidently is instrumental in increasing the dilation of
the terminal part, which dilation, as has already been indicated, seems to be especially great in Spinax.

The 31. extensor is almost as in Acanthias, that is, not sharply bounded from the dorsal part
of the 31. dilatator.

This latter, on the contrary, is on the ventral side distinctly bounded from the 31. adductor
by a line running obliquely from the lateral side down towards the medial side. Its aponeurosis, as
in Acanthias, is especially attached to Td and Tv.

The glandular bag (the 31. compressor) does not in any of my numerous specimens reach quite
to the pelvis, and accordingly it must be termed proportionally small. Its < outer lip-muscle as usual
originates from the piece ft and the hindmost rays, and is with its principal portion very distinctly
inserted on the piece Tv 2 , with another portion on the folded part of the ventral marginal cartilage
(not on the thorn T 3 ).

Scymnus lichia Bonap.

A skeleton in the Zoological Museum (from V. Fric in Prague).

In this specimen the appendix only reaches a trifle farther backward than the fin-membrane,
and the condition of the terminal skeleton makes it probable that the organ is not fully developed.

< ix THE APPEXDICES GEXITALES (CLASPERS) IX THE SELACHIANS.

Between the basale and the appendix-stem is found one piece b z bearing the two hindmost
ravs. The piece /? is rather large, flattened, with an edge turned towards the dorsal side.

The appendix-stem is as long as B ->- ^; its proximal part below the knee is somewhat bent,
medially convex, otherwise of a similar form as in the Greenland Shark, i.e. distally lanceolate; the
end-style is very short. The dorsal marginal cartilage is a very narrow ridge, reaching forward almost
to /?; the ventral one is much longer than in the Greenland Shark, occupying almost the whole
length of the appendix-stem as a rather high, firm, and hard lamella, the distal part of which forms
a but small, very narrow, folded plate, properly speaking only an indication of such a one.

Among the terminal pieces the piece Td is still quite soft, not separated from the other tissue;
Tv on the contrary is hard, and reminds, as to its form, of the corresponding piece in the Greenland
Shark. T 3 is present, but small, and no doubt not yet quite formed; whether in the developed organ
it is hidden by the soft tissue - so that the observation by Miiller & Henle: Die maunlichen
Anhange ohne Stachel (I.e. p. 91) so far may be justified -- I must leave undecided; the observations
of these authors concerning the ventral appendages are however, as it turns out, often quite unreliable.

Scylliidce.

Scyllium canicula (L.).

(PL II. fig. 16, 171.

The copulatory organs are mentioned by several authors, generally, however, without any par-
ticular description, as these authors especially attach importance to one peculiarity in the ventrals of
the male, which (in all stages) forms an easy distinctive mark between Scyllium canicula and Sc. stellate
(catulus) 1 ), viz. that the ventrals are completely coalesced dorsally of the appendages, and in the
middle of the hindmost edge of this coalesced part only a small incision is found. Bv a fold
of the fin-membrane, passing over the proximal part of the appendages, these are also partially
covered on both sides ventrally, and thus they are placed as tongues in a bell, which is open on the
lower side, their hindmost ends reaching to or even farther (abt. 5""") than the hindmost edge of the
bell 2 ). The whole dorsal side (i.e. the side towards the body) of the coalesced ventrals is covered
with dermal teeth and pigmented (spotted like the skin of the animal in other places), and this cover-
ing is continued round the edge to the ventral side, where it is quite sharply limited; the other ven-
tral part of the coalesced fins (the part in contact with the dorsal side of the appendages) is naked,
unpigmented, and soft.

The appendix (in two specimens, when measured from the cloaca, abt. 43'™ long, abt. 6 mm
broad at the base of the terminal part, which is of a length of abt. 24"' m ) is straight, posteriorly some-

') See for inst. Miiller & Henle, I.e. p. 7, 10. Kroyer, I.e. p. S24. Dumeril, I.e. p. 316, 317. Lilljeborg,
I.e. p. 650. Petri, I.e. p. 303. and fig. 6.

■ words of Lilljeborg 1. c. p. 650: The male has small copulatory organs, not reaching to the hindmost points
of the ventrals. ami scarcely of half of the above given length of these fins ■ do not apply to the developed state. Xeither
can the figure 6 of Petri represent the developed appendages, and it is upon the whole bad; the appendages are in this
species never so clumsy; the description at p. 303 is only ill adapted to Sc. canicula, and nut very well to Sc. catulus.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIAN'S. 33

what conically tapering, on the greater part of the surface covered with dermal teeth; only immediately
at the cloaca the dorsal side is naked, as is also the outermost point of the appendix, which is soft and
papillous; from here a naked, depressed stripe reaches forward on the medial side of the terminal
part')- On this part the dermal teeth have another shape than elsewhere on the animal, being longer
and more pointed, like small thorns with the points turned towards the base of the appendix;
accordinglv the hinder part of this is rough to the feeling wdien rubbed backward, contrary to what
is the case elsewhere on the animal. The appendix-slit is covered in the terminal part by a thin,
soft membrane arising from the dorsal (inner) lip; when this membrane is thrown back, the furrow
is found to be open as usual; but above the terminal part it is only represented by a groove in the
skin, not verv deep; the slit, which in the Sharks, hitherto mentioned, is quite open, is in this animal
under the dermal furrow by coalescing formed into a tube reaching to the base of the organ near
the cloaca, and first here an opening is again found, an oval aperture through which a sound may
be brought into the glandular bag. This latter accordingly has two outlets, one at the base of the
appendix, the other between the movable parts of the terminal part 2 ).

The skeleton. Between the basale and the appendix is found one very small piece (<^)
bearing 110 rays; the piece [i is also inconspicuous, somewhat triangular, with a broad articulation
before with the basale, a narrow one behind with the appendix-stem.

The appendix-stem is of about the same length as the basale; it is calcified to a rather
considerable degree; the soft end-style reaches to somewhat more than half the length of the
terminal part.

Both marginal cartilages are specially strongly and peculiarly developed, which will be seen from
fig. 16 clearer than from a description. The dorsal one (Rd) reaches (as is usual) somewhat further
forward than the ventral one, but in the dorsal middle line it joins with the latter for a long way by
a firm <■ suture , so that the two cartilages together with the stem form a complete, firm tube, open
before where the glandular bag joins it, and behind at the terminal part. Thus the part of the ventral
marginal cartilage assisting in the forming of this tube, corresponds to the folded plate of the ventral
marginal cartilage in the before mentioned Sharks 3).

The number of terminal pieces is four^), completely corresponding to those in Acanthias.
Td is narrow, somewhat triangular; along the side towards the furrow it is connected with a thin,
style-shaped piece, Td 2 which proximally becomes broader, and reaches a little under the dorsal mar-
einal cartilaee. Tv is broader, lenglheiied-oval, rounded on the outer side, towards the furrow slightly
hollow, thick, and solid. Between its proximal end and the ventral marginal cartilage is inserted a
well developed piece, T 3 , which is not formed as a thorn, nor can it be erected to such a position, as

') At x in the fig. 6 of Petri.

2 Daw, J.: On the Male Organs of some Cartilaginous Fishes, Phil. Tr. vol. 10, 1839, p. 146, has already mentioned
this fact in Scyllium Edwardsii\ Petri represents it 1. c. p. 304.

1 As Petri has not seen the marginal cartilages as such in Acanthias, he has in Scyllium understood them to be
something particular in this genus.

11 When Petri also finds four pieces in Scyllium it arises from his counting the end-style of the stem (b'" fig. 7, C);
he has really overlooked one piece, viz. Td 2 .

The Ingolf-Expedition. II. 2. 5

34

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

the corresponding piece in the hitherto mentioned Sharks. All these terminal pieces are hard, white,
china-like, tmt none of them protrudes with any part through the skin.

The muscular system is as in Sc. stellare, where it will be more particularly mentioned.

Scy Ilium stellar e (L)

i PL II, fig. 1S-19; pi. VI, fig. 65— 66.1
As upon the whole the ventrals of the male as to contour and shape are different from those
in the preceding species, so it is also the case with the appendices. The ventrals are also here coa-
lesced 1 ), but only for a short way (in one

specimen of the total length of 90='" the

ah /

coalesced part has a length of i6 mra ); the

r~' '"\ small cut in the posterior edge in Sc.

if f^v canicula has here become a large slit

[ (in the specimen mentioned above about

A 26"™); the dermal teeth also spread to a

f '"' W JJr greater extent on the ventral side of this

A w l part of the fin. As furthermore 110 lateral

F Mm •■ Ai fold of the skin is found on the ventral

f J . y'' side covering the base of the appendices,

and correspoudina: to the one mentioned in
Fig. 7. Fig. 8.

Sc. cannula, no shells is formed here.

Fig. 7. Scy Ilium stellar e. The appendage of the right side seen T j 1£ a pp e ndix reaches just outside
from the ventral side; about the natural size, ad abdominal pore.

F fin-membrane, / winglike process. the posterior fin edge; it is far more big

Fig. 8. The same appendage seen from the dorsal side- the coa- ^ du ^^ ^ ^ calllal!a , but still
lesced part of the membrane of the ventral is cut up, and thrown

back. The arrow indicates the direction, in which a sound may be the details remind of the latter, they are

brought into the appendix-canal. , ,

only coarser and more conspicuous.
In a specimen of a total length of 90°'" the following measures were found:

Length of the appendix from the fore-edge of the cloaca to the hindmost point . 6i mm

- - free part 3 6 " ,m

- - terminal part 34 mm

Breadth of the appendix above the terminal part i4 mm

across - - i6 mm

The terminal part is relatively larger than in the preceding species, and its peculiar appearance
is especially caused by the strongly developed process /, which is only indicated in the preceding
species. This process is on the ventral side (fig. 7) hollow , and the bottom of this hollow is naked,
which nakedness continues on the soft, outermost point. The greater part of the appendix is also

M When Lilljeborg 1. c. p. 655 tells that the ventrals in Sc. sicllare are not coalesced, he is not quite right. Miiller
& Henlc I.e. p. 10 state the fact correctly.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 35

here covered with dermal teeth ; besides the parts mentioned only the surroundings of the anterior
aperture of the glandular bag are naked. The points of the dermal teeth are also turned towards the
base of the appendix; they are longest and most pointed on the dorsal side of / and /. The appendix-
slit is closed (to an extent of abt. 1$™°) in advance of the terminal part, as may be seen by throwing
back the dermal lip x — x' in fig. 8; accordingly we have as in Sc.canicula two outlets for the secretion
of the glandular bag.

The skeleton in its main features is as in Sc. canicula, but the appendix-part of it is
much more clumsy and peculiarly twisted. One small b Y without rays, and a little t 3 with rounded
contour are found '|.

The appendix-stem, from the articulation with b 1 to the end of the style, is of the same length
as the basale; it is somewhat bent with medial concavity; the end-style of about half the length of
the calcified stempiece; at the distal end of the former the medial edges of both the adjoining ter-
minal pieces form a rather sharp knee.

The marginal cartilages are principally like those in Sc. canicula; Rd is posteriorly somewhat
longer than Rv, and is distally and medially a little hollow.

The terminal pieces are four, three of them white and hard. Td is formed somewhat like
a roof and as broad medially as Tv is ventrally; Td 2 is mainly as in canicula\ Tv is rounded on the
outer side, somewhat concave towards the slit, T~ in my specimen is not calcified; but a soft,
fibrous cartilage, joining with Tv and placed in the lip /, in my opinion represents this piece 2 ). As
in Sc. canicula none of the terminal pieces are seen through the skin.

The muscular system. From the medial marginal part of the M. adductor have been
branched off two separate muscles : fig. 65, fig. 66 a s and a 2 .

If we look at the ventral side (fig. 65) the fibres of the marginal part are seen as a powerful
muscle a It anteriorly originating from the medial aponeurotic stripe, and posteriorly inserted on the
proximal part of the appendix-stem close to the ventro-lateral edge of the skeletal orifice for the
glandular bag; but part of its fibres attaches to the basale, and another part runs into the M. dilatator.
Looking at the dorsal side (fig. 66) we find the edge formed by another muscle a 2 , anteriorly only
indistinctly separated from a z , but posteriorly distinctly enough, as here a foremost portion of the
J/, dilatator originating from the medial side of the basale, wedges in between both. This muscle a 2
distallv joins with the M. extensor (E), and together with this is inserted by a tendon below the
knee of the appendix-stem.

The M. dilatator is enormously thick, and originates with the greater part of its mass from
the appendix-stem until the boundary of the marginal cartilages, but, as already mentioned, a portion
of it arises from the medial side of the basale; part of this muscle distally joins in the composition
of the peculiar process f (it is the same in Sc. canicula, where this process is much less conspicuous),
which by no means, as Petri says, is composed exclusively of verfilztem Bindegewebe>.

') Petri 1. c. fig. 7 C has distally of fl (r in Petri) another little piece (r"), which is not found at all in my specimen,
and which upon the whole I do not think to be normal (originating from a rupture?); furthermore a piece [mr) which he
(p. 3051 compares to a knee-cap »; this is, however, scarcely to be regarded as a particular piece, but, I suppose, only a strongly
calcified eminence on the stem.

2 ) Petri, fig. 7 C, x.

36

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

M. compressor. The bag-formed part of this muscle is rather long, and reaches considerably
forward of the pelvis. On the contrary, the part forming the outer lip-muscle is rather small
(smaller than in my figures); as usual it originates from the stem-skeleton (/?) and from the hindmost
ravs, and is inserted on the proximal edge of the ventral marginal cartilage; it will here scarcely be
able directly to contract the dilated terminal part 1 )-

Pristiurus melanostomus (Bonap.).

(PI. II, fig. 20, 21.)

The ventrals of the male of this species are also dorsally coalesced in a similar manner as in
the preceding two Scylliidse 2 ), but to a still less extent than in ^SV. stellare, and a deep curve separates

the coalesced part into two fin-laps. The appendices reach far behind the fin-
membrane 3), in a specimen of the length of 78 cm to 23™'" behind the point
of the fin-membrane; the whole length, from the hindmost edge of the
cloaca, is 50 mm ; the part quite free of the fin is 35 mm long; the largest
breadth of the organ is about 7'"'"; the terminal part has a length of about
25""". The ventral side is covered with dermal teeth, except the hindmost,
soft, as it were, convoluted part (abt. o, mm long), on which still scattered
groups of teeth may be seen; the dorsal side is naked, as are also the
adjoining parts of the medial side, where they are covered by the fin-
membrane; on the free edge of the lip / a few scattered rows of dermal
teeth are seen. The dermal teeth are generally very fine; as in the fore-
going species their points are on the terminal part turned towards the
base of the appendix. The dentition on the coalesced fin-parts is as in
Sc. stellar e.

The peculiar appearance of the appendix will be seen with sufficient
distinctness from fig. 9. The furrow anteriorly is opened by a large, easily
distended slit of a length of 8 — io mm ; behind this slit it is closed for an
equal length, and again open in the terminal part. In spite of the great
dissimilarity in general when compared with the appendix of the preceding
Scylliidse, a closer examination will show a rather considerable similarity with
these, especially with Sc. stellar e\ corresponding to the peculiar process / of the Scyllia is found a thin,
soft dermal process, which may be folded towards the furrow (as in fig. 9), or spread in a wing-like

■1 This part of the M. compressor has been quite overlooked by Petri, who has seen and drawn the other muscles,
and given them the following names (see I.e. pi. XVII, fig. 7. A and B|:

The muscle here marked ./ (the chief portion of the .1/ adductor) — ft.m.p. i.e. flexor major pinna.

— - — a.1 = fl.p.b. i.e. flexor pterygopodii biceps.

— - — a 2 = fl.p.ex i. e. flexor plcrygopodii exterior.
The M. extensor here marked E =■ ft. p. i. i. e. flexor pterygopodii interior.

What Petri calls flexion must, I think, rather be regarded as an adduction connected with an extension of the appendix.

-) The expression used by Lilljeborg I.e. p. 66o their inner edges are not coalesced) is accordingly not quite
correct. Tin- appendices are shortly described at p. 662.

1) Comp. Gunnerus: Om Haae-Gaelen, pi. I, f. (Trondhjemske Selsk. Skr., II.)

Fig. 9.

Pristiurus melauostomus.
The right appendage seen
from the dorsal side; about
the natural size. The fin-
membrane is cut through,
and thrown back. the
larger basal opening of the
appendix-slit; between the
asterisks it is closed by
coalescing. The other signs
as in fig. 8.

ON THE APPENDICE.S GENITALIAS (CLASPERSl IN THE SELACHIANS. 37

shape to the medial side; to the lip / which in the Scyllia is turned into the furrow, corresponds
the part in Pristiurus marked with the same letter, to the naked dermal fold i in one corresponds the
naked dermal fold i in the other, etc.

Also the skeleton shows the near relation to the other Scylliidse. Between the basale and
the appendix is found (ventrally) a very small, quite rudimentary piece b l which of course bears no
rav; dorsally is found an also very small piece t j.

The appendix-stem and the marginal cartilages are much like those in the Scyllia. The
stem is twisted longitudinally in a similar manner as in Sr. stellare, but is not bent medially. The
dorsal connection of the marginal cartilages, however, is not so close as in the Scyllia; the two
pieces may here be forced a little from each other.

The number of terminal pieces is five, if to the terminal pieces we will count a piece, Rd 2 ,
which has not been found in any of the Sharks, mentioned in the foregoing; it is joined movably to
the hindmost edge of the dorsal marginal cartilage, and is situated in the dermal fold below the
asterisk in fig. 9.

Td and To are long and narrow, and form at the end of the style a similar kueeshaped curve
as in Scyllium stellar,: (in Sc. canicula it is only indicated); a slightly calcified or almost quite soft
piece Td 2 is found, projecting forward under the edge of Rd; To proximally forms a rather broad
plate, to the dorsal edge of which is attached a leaf-shaped, somewhat bent piece T v All the pieces
are completely hidden in the skin.

The muscular system is substantially quite the same as in the Scyllia, the only
difference being that the « outer lip-muscle seems to be still less developed in Pristiurus.

La inn idee.
Lamna cornubica (Gmelin).

1 PI. II, fig. 22, 23.)

In a specimen of the length of 2 m 5 c,n , which in the beginning of November 1897 was driven
on shore on the western coast of Jutland, the appendix has a length of 2i cmI ) and a largest breadth
of 4 cm ; the terminal part is 7,5 cm long. The whole ventral surface is densely covered with dermal
teeth quite to the end; this investment ceases with a strongly marked boundary line on the medial
surface, which is quite naked to the terminal part; this latter being almost quite covered with teeth
until the margins of the appendix-slit, also on the dorsal side; the other parts of the flat dorsal side
of the shaft are naked, and these naked parts are laterally marked off from those covered with teeth'
by a rather deep longitudinal dermal fold. Apparently the appendix-slit from before the terminal part
and to a larger foremost opening at the base of the appendix is closed as in the Scylliid<B\ but in
reality it is open, and for the whole way it is possible, though with difficulty, to press a sufficiently
thin sound in between the margins of the marginal cartilages. On the medial side, immediately be-

1 I.illjeborg 1. c. p. 625 gives for a specimen of the length of 2,4m a length of 2,5<:m for the appendix.

<Cv

38

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

fore the terminal part, is seen a small opening (/ in the fig. 10 in the text) of a length of i 1 2 cm ; this
opening leads into a deep, pocketlike invagination of the skin, lined with a soft continuation of this,
similar to a mucous membrane. On the dorsal side of the terminal part, at the lateral base, a polished
skeletal piece projects uncovered by the skin and like a thorn (T). The terminal part is easily bent
ventrallv; if bent in that way, the thorn, as in many other Sharks, will rise mechanically, and stand
out horizontally; it will immediately lie down again, when the terminal part is let loose. A dermal
fold supported by the skeletal piece Td, is prolonged forward into the tube formed by the marginal
cartilao-es in such a manner, that this tube gets two outlets, one on each side of the lamella concerned;
but the appendix-slit proper is situated laterally of this piece (a/ in fig. 10).

The skeleton. Between the basale and the skeleton of the
appendix is found (almost as in the Scylliidse) one very small piece 6 Z ,
highest on the medial surface, and otherwise quite low, that is to say,
wedge-shaped; in connection with the distal end of the basale and the
proximal end of the appendix-stem it bears the hindmost ray, which at
the base is rather broad. The piece ft is pretty well developed, and, as
is usual in Sharks, connects the basale with the appendix-stem.

The appendix-stem is very long, twice as long as the basale
+ b s \ proximally it is only a little calcified (comp. Selackus), but else it
is firmlv calcified in the surface until the terminal part, where it forms
a very long style, reaching to the hindmost end of the terminal part;
this style for the hindmost two third parts is calcified in the surface;
its soft basal part is situated immediately under the above mentioned
pocket ■; the distal end of the Musculus dilatator passes into the firm,
fibrous ventral wall of this pocket, in such a manner that its aponeurosis
is firmly inserted in the perichondrium above the calcified part of the
style, as well as in the corresponding places of the two adjoining calci-
fied terminal pieces Td and Tv\ the soft part of the style and the joints
between the marginal cartilages and the two skeletal parts Td and Tv
will then act as a kind of articulation 1 ).
The marginal cartilages are very long, hard, and thick; forward they reach almost to the be-
ginning of the appendix-stem; the dorsal one reaches somewhat longer forward and also somewhat
further backward than the ventral one. In the greater part of their length the two cartilages are in
contact with their margins; proximally the dorsal one is covered a little by the ventral one, the
margin of the former being bent somewhat into the tube enclosed by both; behind, a little before the
terminal part, they separate, and leave between them a slit broadening distally.
The number of terminal pieces is four.

'I'd and Tv are long, almost equally developed; their distal ends are not calcified, and do not
reach quite to the end of the style. To the inner dorsal edge of Td is attached a piece Td 2 , which

Fig. 10.

Laniita cornnbica. The hind-
most part of the right appen-
dix seen from the dorsal side;
considerably reduced. / the
opening of a pocketlike inva-
gination of the skin. Tv, a
dermal fold containing no ske-
letal piece.

M If we should suppose a skeletal part to be developed in the ventral wall of this pocket, it would in all respects
be corresponding to the covering-piece v found in Rkina.

ON THE APPENDICES GENITALES (<XASPERS) IN THE SELACHIANS. 39

is a rather thick lamella only partly calcified. Also a piece Tv 2 is indicated as a pretty long, thin
lamella, which does not calcify or only calcifies to a very small degree (see fig. 10 in the text); it is
connected with the proximal end of 7w, stretches forward inside the thorn , and is with the anterior
end firmly united with the aponeurosis, on which the outer lip-muscle , bespoken afterwards, acts;
by the pulling of this muscle at Tv 2 and Tv the dilated terminal part is brought back, and the thorn
T, situated between the two said pieces is laid. T, has more particularly the form of a claw, whose
proximal part is head-shaped and rather soft, wrapped in the soft tissue connecting it with the adjoin-
ing pieces.

The muscular system. The Jk. adductor is distally not sharply separated from the M. dilatator^
as part of the fibres of the former passes into the superficial medial layer of the latter. The former
muscle is quite woven together with the M. extensor, so that it is only by preparing from the dorsal
side far into the large, proximal muscular mass that a considerable portion of fibres is found, origin-
ating from the basale, and having a direction common in the J/, extensor.

The bag-shaped part of the J/ com pressor is very long and rather thick; in the specimen
examined by me, it is about 40'" long, of which 23°'" are situated under the ventral skin before the
pelvis 1 )- The outer lip-muscle shows the peculiarity that in spite of the long ventral marginal car-
tilage it is prolonged covering the dorsal surface of the said cartilage until the terminal part, where
it acts on To by means of the above mentioned lamellar indication of a Tv 2 in a similar manner, as
this muscle acts in Sharks with a short ventral marginal cartilage.

The J/, dilatator only covers a very small part of the dorsal side of the appendix-shaft, by far
the greater part of the dorsal marginal cartilage being covered only by the skin.

Selachus maximus (Gunnerus).

The appendix has been briefly mentioned by Sir Everard Home 2 ), somewdiat more detailed
by Blaiu villeJ), but not originally by Pave si 4), whose specimen, however, was a male; only in
his second paper?) does Pavesi briefly describe and draw (p. 353) the (undeveloped) appendix, and
collects the whole literature treating of these organs, giving also in a table (1. c. p. 406) the dimensions
that mav be put together according to the obtained facts. The image of the appendix that is to be
got from the literature, is upon the whole only imperfect. I have not found any particular mentioning

M The glandular bag contained only a little mucus, while the tube of the appendix, and the above mentioned pocket
.1-, well as the inside of the terminal part were all filled with an extremely viscid, milk-white mucus, which made the fingers
exceedingly slippery and was difficult to get washed off; it contained numerous cells of different size and shape, with oval
or round nuclei staining very readily.

2) 1) An anatomical Account of the Squalus maximus etc. Phil. Trans., 1809, S. 207. 2) Additions to an Account etc.
Phil. Tr., 1813, S. 230. Among other things the glandular bag is here mentioned as a cavity between the skin and muscles
of the abdomen, eleven feet long and two wide. The inner surface of this cavity is smooth, almost polished, and of a
beautiful white colour; it contained a white mucus, extremely viscid and tenacious.

3) Memoire sur le Squale Pelerin. Ann. du Museum d'Hist. Nat, T 18, 181 1.

n Contribuzione alia storia naturale del Genere Selache. Ann. del Mus. Civico di Genova, vol. 6, 1S74.

5) Seconda Contribuzione alia Morfologia e Sistematica dei Selachi. Ann. del Mus. Civico, vol. 12, 1S7S. Besides
the drawings quoted here one more drawing is found, only, however, a sketched outline, of evidently undeveloped appendices
of a Squalus maximus », in Cams und Otto: Erlauterungstafeln zur vergl. Anatomic Part 5, pi. V, fig. VIII, 1840.

4 o

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

- R,l

Rv —

Fig. II.

of the skeleton, but the following will, noth withstanding it defectiveness, show, that the structure of

the skeleton is like that of Lamna.

In the museum of Copenhagen is found a pair of dried skeletons of these organs that

have been got from a stuffed specimen (from California) of the length of g m 15°™ (2y I / 2 Danish feet).

By long soaking the dried softer cartilaginous parts
swelled so much that upon the whole they might be
thought to approach to the shape of the fresh skeleton.
Of the parts of the fin skeleton proper is only found
a little, somewhat triangular piece, situated proximally
at the dorsal end of the appendix-stem; it must be the
piece /?, which is accordingly (as presumably also the
piece 6 J quite small as in Lamna (and the Scylliidse) ').
The appendix-skeleton has a length of about
i m2 ); it may be doubted if all the terminal pieces have
been preserved, but the principal features may be seen
distinctly enough. The appendix-stem is calcified (the
proximal end, however, not very much); the soft style
is very long and rather broad, and reaches to the out-
ermost end of the terminal part (comp. Lamna). The
marginal cartilages are developed almost as in Lamna,
that is to say, they join dorsally without forming a
firm suture, the edge of the ventral one overlapping
that of the dorsal one 3). The number of terminal
pieces (in the specimen in hand) is 3.

Td is short, not reaching to the end of the
style; it is calcified for the greater part of its length,
and has on the dorsal surface a furrow or groove /,
wide before, where it passes into the large appendix-
slit, while behind it becomes a narrow slit following the
piece to the end+).

Tv is only calcified anteriorly, otherwise it is a
soft cartilage following the style just to the end. T,

Fig. 12.

Fig. 11. Selachus maximus. The skeleton of the
right appendage seen from the ventral side; much
reduced.

Fig. 12. The same from the dorsal side, f furrow
in the dorsal terminal piece. Both figures have been
drawn after a dried skeleton. The position of 7^ is
scarcely quite correct, and Tv is separated from its
connection with the marginal cartilage Rv.

M Pavesi (1S7S, p. 378, fig. 12) draws the ventral skeleton of a young male; here is only seen the basale, and a
very little developed stem-part of the appendix. As, however, in other Sharks the pieces, which I have here called i t etc.
and /J, are distinctly present in young ones, even in embryos, it is to be supposed that they have been overlooked here; in
Scyllium and Lamna they are so small, that they are easily overlooked, if the skeletal parts are not cleaned of the soft parts
with especial care.

2 ) In the specimen of Blainville it was 3 feet long (the free part); the length of the animal was 29 ft. 4 inch.
1 The words of Blainville 1. c. p. 125 are: • ils offroieut en outre une fente ou sillon etendu dans toute leur longueur,
mais dout la moitie anterieure, d'a peu pres 14 pouces, etoit etroitement ferine par le rebord de deux cartilages tres-serres
et qu'on lie pouvoit ecarter qu'avec une tres grande difficulty.

>i It ma\ possibly he this (?) slit, which is mentioned by Blainville 1. c. p. 126 as a <sillon beaucoup plus

petit el plus etroit etc.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 4I

is claw-shaped and of a considerable size (in the specimen before me i6 cm long, and the broadest part
5,6 cm broad); with the exception of the proximal part it is completely calcified; according to the state-
ment of several authors 1 ) the point of it (in the developed organ) projects through the skin.

Besides the three terminal pieces seen in my figures, I think it probable that one more has
been found, a Ti/ 2 as in Lamna. I found this opinion in the first place on the words of Blainville
(I.e. p. 126) that besides the claw there is tun autre cartilage, un pen aplati, occupant le milieu du
tiers anterieur de cette gouttiere (i.e. the furrow of the terminal part); celui-ci etoit mobile presqu'en
tons sens, mais entierement renferme dans un repli de la membrane interne qui se prolongeoit, libre
et flottante, jusqu'a l'extremite posterieure du sillon . Next I found the above stated opinion on the
description (1878, p. 352) and drawing in woodcut (fig- 3) of the [undeveloped) appendix given by
Pave si: nella meta apicale offrono un pezzo mediano lanceolate, rialzato e piano, con fenditure laterali.
Ouesto superficie non ha traccia di sperone corneo ». Later (p. 405) it is said of this piece that it is
only a thickened dermal fold, not to be confounded with «the spur» 2 ). The dermal fold mentioned
by these authors, no doubt corresponds with that one which in Lamna contains the piece Td 2 . But
what is the fenditure laterale of Pavesi? According to the figure it must be situated ou the medial

side of the organ, that is to say, it is presumably the sillon beaucoup plus petit et plus etroit»

of Blainville; and thus it must be supposed to be the one seen in the skeleton, fig. 12/, and not
a «pocket like the one described above in Lamna, because this latter is situated before the terminal
part, and accordingly would be seen on the part called by Pavesi la meta basale .

Rhinidce.

Rhina squatina (L-).

(PI. II, fig. 24-27.)

In a specimen of the length of i m and a breadth across the pectorals of o,59 m , the part of
the appendix free of the fin is S 1 //'" in length; from the foremost beginning of the slit the length is

') Shaw: General Zoology V, pt. II, Pisces, 1804, tab. 149 (in the text nothing is found about it); the figure is
certainly bad, and the appendices can scarcely ever have that appearance, but are, to use the words of Pavesi (1878, p. 404), < tras-
fonnate in sorta di gambe dall'imaginoso disegnatore . Blainville gives it to be 7 inches long, but covered by soft tissues
except ■ 2 inch, which ni'a paru comme cornee et libre au bord superieur et exterieur de l'appendice . Home speaks of
it as a strong, flat, sharp, bony process, five inches long, which [moves on a joint, and the bone projects an inch and
a half beyond the skin, like a spur. (1809, p. 207); in the later addition is only said: < the spur bears a striking resemblance
to that of the male ornithorvnehus paradoxus. Lesueur: Description of a Squalus etc.; Journ. Acad. Nat. Hist. Philad. II,
part II. 1822, p. 349; Mitch ill in Dekay: Natural History of New York, Zoology, part IV, Fishes, 1S42, p. 35S: From and
between the anal fins, two legs project five feet in length, and are terminated by a claw tipped with horn». Van Beneden:
Un mot sur le Selache (Hannoveraj aurata du crag d'Anvers; Bull. Acad. Roy. de Belgique, 2 Serie, vol.42, 1S76, draws a
sketch of the appendices with the spur from a stuffed specimen in British Museum, and shows that these spurs are (as
well as the gill-rakers) found as fossils in tertian- strata. Before I knew this fact and the paper by van Beneden, I have
expressed, in a lecture given in the Society for Natural History in Copenhagen (March 1897), the conjecture that the very
hard, dentine-like terminal pieces of the appendices of Selachii might exist as fossils, and indicated that perhaps some of
the ichtyodorulites were not dermal teeth (spines) but such skeletal parts; by turning over the work by Agassiz on
fossil fishes I have, however, not been able to find any drawing, to which this conjecture might be applied.

-I Pavesi himself thinks the presence or absence of this latter to be dependent on the age of the animal, and not
to indicate a difference of species, and it is now beyond all doubt that this opinion is quite correct. All other species of
Sharks that are provided with a similar spur (as Acantliias, Spinax, Somniosus a. o.) show that this piece is formed hidden
in the skin, and is not uncovered until it has reached a considerable degree of development, contemporary with the organ
as a whole having altered its shape and dimensions.

The Ingolf-Expedition. II. 2, o

42

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

y

— - E

Fig. 14.

n,5 cm (from the foremost edge of the pelvis to the hindmost point of the appendix the length is
24 cm ) z ); the largest breadth is found somewhat above the hindmost point of the fin-membrane, and is

about 3,5 cm . The ventral side is flat,
covered with dermal teeth till the
naked terminal part (4,3 cm long,
2,i cm at the broadest spot, at the
base); these dermal teeth are flat,
and form a complete mosaic, only
a little rough to the feeling, when
rubbed with the finger towards
the base, and it is of cpiite the
same nature as that covering the
ventral side of the rest of the fin 2 );
the whole surrounding of the clo-
aca as well as the space from
there to the foremost lateral corner
of the fin is naked (with a few
scattered groups of teeth); further-
more a naked stripe stretches
from the hindmost inner edge of
the fin-membrane, where the fin
is laid against the appendix, some
way on the ventral side of the
fin. Both edges as well as the
whole dorsal side of the appendix
are naked.

The somewhat triangularly
pointed terminal part shows, when
seen from the dorsal side, the appendix-slit (of) situated near the lateral edge; a rather large, foliace-
ous fold of the skin, which includes the skeletal piece Td 2 , originates from the dorsal lip of the slit;
the proximal end of this fold stretches into the (half-) tube formed by the distal ends of the marginal
cartilages. Accordingly there will, on both sides of this plate, be an outlet from the canal of the
glandular bag in the broad part of the appendix; the real continuation, however, of this canal is
here, as everywhere, situated in the terminal part laterally of the said fold (at of). If the fold
is thrown back, there will in the lateral margin of the appendix-slit proper be seen a rather large

M Mi'iller & Henle I.e. p. 99 state in characterising the genus: Die Anhange des Mannchen klein und weich ,
which, as we have seen, does not apply to adult animals, and consequently is of no value as a characteristic of the genus.

-) This dental mosaic on the ventral side is quite different from that of the dorsal side, where the dermal teeth
project as small thorns from the thicker skin. The words of Miiller & Henle in characterising the genus: • ■Schuppen
konisch in erne Spitze endigend, zerstreut are then only to be applied to the dorsal side. I have not upon the whole
found any mention made of the dermal teeth of the ventral side, only expressions to the effect that the abdomen is more
or less smooth.

Fig- 13-

Fig. 13. Rhina squatina. The left appendage from the dorsal side, reduced.
The part from a to b has been cut up in prolongation of the appendix-slit to
open this latter so much as to get a view of the gland k. /' is part of the
entrance to the pocket between Tv and v.

Fig. 14. A transverse section through the same appendage after the line,
marked with * x- in fig. 13. b the transverse section of the appendix-stem. D
Musculus dilatator. E Musculus extensor. S Musculus compressor. k the
gland, v blood-vessels. // horny filaments, r the end of the last ray.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 43

aperture (at /') leading into a pocket between the ventral terminal piece (Tv) and the ventral
covering piece v.

If the lateral lip of the appendix-slit above the terminal part is lifted, a thick glandular
body is seen protruding from the medial side of the canal, in which feature this species differs from
all other Sharks I have had the occasion to examine. This gland will he more particularly mentioned
afterwards.

The skeleton. Between the basale and the appendix-stem three short pieces (b 1 , b 2 , and b.)
are found, each bearing one of the three hindmost rays (the two hindmost of these rays are termin-
ally quite coalesced for a long way). At a first glance the piece /? seems to be wanting, but a closer
examination shows it to be present, represented by a little cartilage, arising from the lateral hind
corner of b,, and joined by a particular articulation to the proximal end of the appendix-stem b. Con-
trary to what commonly is the case in the Sharks, the piece j) does not here articulate proximally
with the basale.

The appendix-stem (b) is long, considerably longer than the basale (the ratio is 3/ 2 ), round
(with the exception of the proximal part where it dorso-ventrally is somewhat flattened); the style is
long, not, however, reaching to the hindmost point of the terminal part. The marginal cartilages are
short, and are only found at the distal part of b; contrary to what commonly is the case in the
Sharks, the ventral marginal cartilage is the one reaching most forward. The general shape of
these cartilages, I think, may be seen with sufficient clearness from the figures. The ventral marginal
cartilage bends towards the dorsal one with a plate similar to that found in many other Sharks, but
does not cpiite reach it. But this plate is here in a peculiar way hollow, being behind split into two
lamella? receiving between themselves the proximal end of the piece Tv; this piece, then, projects into
the ventral cartilage, quite covered, until the point marked * in fig. 25 : ). The hindmost end of the
inner one of these two lamellae protruding very much, the appendix-slit is by its transition to the
terminal part straightened to an extraordinarily narrow passage.

The number of terminal pieces must in reality be taken to be four; but to these four is
added a good-sized, ventrally situated piece, v, rounded in a scutiform manner, and partly covering
the terminal part (see fig. 24) behind the ventral marginal cartilage. This piece has developed in the
aponeurosis which, in the Sharks hitherto mentioned, encloses the terminal part, and it serves like
this aponeurosis for inserting the large AIusc. dilatator. If this piece v is removed, the ordinary ter-
minal pieces are easily recognized: Td which is rather broad, flat, with a thickened edge medially
(which edge follows the style closely, but reaches a little further backward), and a sharp and thin
edge laterally; Td, proximally joined to the foregoing piece, is a broad, but thin, and but slightly
calcified lamella. Tv is of a very peculiar shape, thick and solid, ventrally rounded, dorsally, towards
the slit, deeply hollowed in a spoon-like shape ; its proximal end, as already mentioned, passes its arti-
culation with Rv, and enters between the two lamelke of the overlapping plate; with the proximal
end articulates, completely hidden, a little calcified piece representing the thorn or spur , 7^,; this
latter piece (see fig. 27) is proximally irregularly head-shaped, and from this thick part a thinner one

i) If in Acanlhias or Spinax the projection of the ventral marginal cartilage, mentioned at p. 2S, was more developed,
and proximally prolonged, a similar state of matters might be the result.

6*

.. ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

projects, bent at its rise, but otherwise straight, cylindrical, and rounded posteriorly. It is necessary
in order to get a view of this piece T 3 , and to isolate it together with Tv , to cut away part of the
outer lamella of the ventral marginal cartilage.

The muscular system. The M. adductor shows no deviations from the common type; the
J/, extensor, on the contrary, shows the peculiarity of being divided into two independent muscles
(comp. Torpedo), an inner (medial) one, and an outer (lateral) one, bordering on each other, and both
originating from the basale; the inner or foremost one arises rather far forward on the basale alone,
runs, like the 31. extensor in the Greenland Shark, across the appendix-knee, covering as a thin plate
part of the dorsal side of the J/ dilatator, and ends quite posteriorly, at the terminal part. The outer
or hindmost extensor arises behind the foregoing one, not from the basale only, but also from the
pieces £ x , b 2 , b 3 , and it is attached to the appendix-stem immediately behind the knee .

The M. dilatator, as is commonly the case, encompasses the appendix-stem from the dorsal
marginal cartilage to the ventral one; the lateral part of it arises forward on the ventral side of the
basale and the short pieces following this latter (comp. the Rays); behind its chief portion is attached
to the ventral covering piece v.

Of the M. compressor the bagshaped part is rather short, and does not nearly reach to the
pelvis, but otherwise it agrees with the one found in other Sharks. The outer lip-muscle- is very
powerful as in the other Sharks with a short Rv, and is attached posteriorly chiefly in the aponeurotic
covering of the piece Tv.

The secreting part of the glandular bag shows in its foremost part the same relations as
in the other Sharks; but in the part which is situated in the shaft itself, a large glandular body (see
fig. 13 and 14) has been developed on the ventral side. The presence of this gland may already
be guessed by the peculiar exterior of the appendix-shaft; its proximal part shows, when seen from
the ventral side, a peculiar convexity, by which the organ gets a contour not unlike that of a human
leg with a large calf. The glandular body reaches before quite to the beginning of the bagshaped
part, that is to say, much farther than the appendix-slit itself, so that it is necessary to cut up some
way (see fig. 13) in order to get a view of the foremost end; it is a little tapering behind, and reaches
to the terminal part. A slight, longitudinal furrow is found on the free (dorsal) surface about the
middle, and on the edges of this furrow are situated two series of large glandular outlets; a great
number of similar outlets are also found laterally of the furrow, in pretty irregular groups; to the
medial side of the furrow are also some such openings, but apparently in much smaller number. When
the gland is pressed an abundance of mucus will appear as stoppers in the said outlets. The glan-
dular body is composed of dichotomously branched tubes, quite similar to those found in the Rays,
and with quite similar large secreting cells; but they are here grouped in a somewhat different
manner as a consequence of the outlets of the gathering ducts being spread on a much greater space.
The glandular body in Rhiua furthermore deviates from that of the Rays by its ventral position in
the shaft '), and by not having the special muscular coat developed as in those; the part of the J/, compressor
situated at the gland will very likely be able to act in a similar way, possibly only with less force, in Rhiua.

[ i In Torpedo, Narcine, Rhinobaius and Trygon the dorsal glandular body of the bag is continued throughout the
shaft with the same structure as in the bag, but reduced in bulk, and situated along the ventral marginal cartilage. If in
one of those Ray-forms the part of the gland situated in the bag be supposed absent, and the part in the shaft displaced

OX THE APPENDICES GENITALIAS iCI.ASPERS) IN THE SELACHIANS.

45

The peculiar mixture of Shark-like and Ray-like characters that, as it is well known, is found
in RAina, is accordingly increased by several features in the appendages of the male, which features
by the ventral covering piece and the pocket, situated below it, with entrance from a side-slit, and
partly also by the glandular bag, recall those in the Rays (Torpedo, Narcine, Rliiiwbatns and Trygon\
while most of the other features are those common in other Sharks.

Cestraciontidce.

Heterodontus (Cestracion) Phillipi (Cuv.).

The skeleton has been described by Gegenbaur 1 ;. Between the basale and the appen-
dix are found two pieces (b t , b 2 = /?, /?', I.e. fig. 18, io| that bear no
rays; the piece fj is well developed (1. c. b fig. 19). The chief piece of
the appendix is provided with two (rather long?) marginal cartilages (the
boundary lines of which cannot be seen in the figures of Gegenbaur,
as he has not understood the marginal cartilages to be particular pieces),
of which the ventral one has a dorsally bent plate (I.e. fig. 19, a); the
stem is prolonged into a long style reaching almost to the end of the ter-
minal part (1. c. fig. 19, 20, / ). The number of terminal pieces is four: Td
{^=\. c. fig. 19, 20, 0), Td 2 (= 1. c. u), which, as is often the case, is prox-
imally prolonged into the appendix-slit; Tv (= I.e. c) , as commonly,
stronger and thicker than the others, and finally T, forming a short thorn.
Gegenbaur has correctly seen the homologies of these pieces with those
in Acanthias , where , however , he has not seen the piece Td 2 (= u in
Heterodontus). Of these terminal pieces the piece T, is said (1. c. S. 452)
to be hard, while the others, though fully developed, are still cartilaginous.

RJ

Rv(a)

(<*>Z~

(u)Tdi

Td

(»J

-R11

ill

-Tv

-Tvle)

(o)rd--M :

Fig. 15. Heterodontus
Phillipi. The skeleton
of the right appendage.
After Gegenbaurfl.c.
fig. 19I. somewhat re-
duced. The letters pla-
ced in parentheses are
those used bvGegen-
baur. r the last rav.

Notidanidce. 2 )

Chlamydoselachus anguineus Garman.

Fig. 16. Chlamydo-
selachus anguineus.
The skeleton of the
right appendage.
After Gun ther,
somewhat reduced.
The letters in the
rudimentary and one larger intermediate cartilages" {b T , b 2 , b 3 , b 4 i) , none parentheses are the

of which bears any ray. To judge by the figure , there is no piece 8 ; original ones.

Giintherj) has briefly described the appendages and their skeleton,
and given figures of them. Only a third part of the length of the appen-
dages is free of the fin, a as is the case in the Notidanidce generally", and
there is no notch in the hindmost fin-edge, between the membrane and
the appendage. Between the basale and the appendix-stem there are « three

along the ventral marginal cartilage to the lateral surface of the appendix-stem, we should have a similar state of matters as
in Khina. There can scarcely be any doubt that the gland in this Shark and in the Rays — in spite of the difference of po-
sition — are in realitj- homologous. Furthermore the glandular bag in younger stages of the Rays seems to pass through a
stage of development, in which there is, also as to the exterior, a conspicuous similarity with that of the Rhiua, without any
conspicuous longitudinal furrow etc. (see later under Raja iatis).

'1 Ober die Modificationen etc. 1S70, p. 450, Taf. XVI, fig. 18—20.

2 1 I regret very much that my efforts to get ventral fins with developed appendages of Hexanchus or Heptanchus
have been in vain. The figure of the skeleton of Heptanchus ciuereus Ag. given by Fritsch in Fauna der Gaskohle etc.
Bohmens, vol.3, 1895, p. 43 is quite useless. From this figure appears only that at least the two terminal pieces Td and Tv
are found; what Fritsch calls the sporn is the last ray (or rather the two last, coalesced ones). The 1 of the figure, I
suppose to be the piece /J, and it is certainly not the - Letztes Glied des Hauptstrahles ■. The figures of the structure of the
appendages in the extinct Xenacanthida: , given by Fritsch as well in his chief work as in several articles in the Zool. An-
zeigers 18S8— 91, I think to be justified in designating as unreliable; but by means of the published figures alone the real
structure cannot be determined.

1 Voyage of H. M. S. Challenger, Zool., Vol. XXII, 1SS7, S. 2, Tab. LXIV, fig. C,D,H.

46

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

as, however, no figure is given of the part in question, seen from other sides, I cannot regard this absence as quite
certain. The Jong appendix-stem is prolonged to a style reaching to the end of the terminal part. The marginal
cartilages (not understood by G tint her to be particular pieces) appear to have mainly the same structure as in the
Spinacidac; the ventral one has the usual overlapping plate (I.e. T. LXIV, fig. D, D\ I). The number of the terminal
pieces is only two (if not a piece T 3 has been overlooked or removed by the preparation?) viz. Td and Tv , both
hard and calcified , Tv being as usual largest and broadest.

Rv

Carchariidce.

Mustelus antarcticus Gthr.

A pair of dried skeletons of ventral fins with appendages in the Zoological Museum at

Copenhagen.

Between the basale and the appendix-stem one rather small piece b 1 bearing the last ray,

which is partly coalesced with the last but one; a distinct, well developed /? that seems to have been

triangular. The appendix-stem is prolonged to a long,
soft style reaching almost to the hindmost end of the
terminal part. The marginal cartilages stretch over the
hindmost two third parts of the chief piece, the dorsal
one reaching farther forward than the ventral one; the
edges of their folded parts join dorsally, leaving between
them only a narrow slit. To the distal end of the dorsal
marginal cartilage is added a foliaceous, slightly calcified
piece, homologous with the piece Rd 2 mentioned in Pri-
st iurus.

The number of terminal pieces is 4 (-f- 1).
The two of these pieces that as usual follow the
style, and together with it form the walls of the hind-
most part of the appendix-slit, Td and Tv, are well cal-
cified, lengthened, pointed, and Td a little longer than Tv.
To the lateral edge of Td is proximal!}- added a foliaceous,
slightly calcified piece Td 2 , forward stretching under the
piece Rd 2 into the appendix-slit as in several other Sharks.
Finally there is a rather large, flat, triangular, posteriorly
taplike piece T, that, however, does not not appear to
have projected through the skin as a < spur .

Besides these real, typical, terminal pieces still a
special piece, v, is found, which I take to be corresponding
to the one marked with the same letter in R/ti/ta, and
accordingly to have arisen from the aponeurosis of the

Muse, dilatator; here in Mustelus antarcticus it covers a peculiar, rather deep, spooulike hollow on

Tv

Fig. 17.

Fig. iS.

Fig. 17. Mustelus antarcticus. .Skeleton of the
right appendage, seen from the ventral side; about
the natural size, v the ventral covering piece; *
a spoon-like hollow in the ventral marginal car-
tilage.

Fig. iS. The same preparation from the dorsal
side; * the bottom of the hollow in the ventral
marginal cartilage, protruding into the appendix-
slit Both figures have been drawn after the dried
skeleton.

ON THE APPENDICES GENITALES iCl.ASPERS) IN THE SELACHIANS. 47

the ventral side of the end of the marginal cartilage Rv (on the dorsal side the corresponding spot
is seen protruding into the appendix-slit, at * in fig. 18).

The descriptions of different Sharks given in the preceding section will have shown that the
common tvpe in the skeleton is clearly conspicuous; the single secondary skeletal pieces may vary
pretty much, as to their form, but their homologies are easily and surely demonstrated. Although
the mentioned species of Sharks cannot be said completely to represent the Sharks upon the whole,
yet they belong to so many different families that we may be justified in coming to the conclusion
that the skeletal structure of the appendix is in the Sharks rather simple and easily explained. This,
however, can in no way be said of the Rays in general; here, especially in the genus Raja,
may be found particularly complicated structures varying to a high degree even from species to
species; and as the Raja - species are those that have been especially examined by earlier authors, it
will easilv be understood that so few general results have hitherto been obtained. If, however, by
means of the Sharks we have got a clear understanding of the characteristic common features, it will
not be so verv difficult to point out these features also in the Raja-. It is, however, an obvious suppo-
sition that other forms of Rays than Raja will approach more nearly to the Sharks, and such forms
will most likely have to be sought among the shark-like Rays, as Rrisf/s, Rhinobatus , Torpedo, etc.
Throueh the kindness of Professor L tit ken I have from our museum obtained the material of the
two last-named genera, and of Torpedo I have also got some pairs of veutrals from Napoli.

Batoidei.

Torpedinidce.
Torpedo marmorata Risso.

(PI. Ill, fig. 2S-31.)

The appendix, like the whole fish, is naked, flattened, with tolerably parallel sides, the termi-
nal part oval, distinctly marked off from the shaft by a slight constriction. The appendix-slit runs
on the dorsal side quite straight, nearest to the lateral edge until the hindmost half of the terminal
part where it suddenly bends to the medial side, and with a curve reaches to the end. On either edge
of the terminal part is seen a lengthened slit, posteriorly widening somewhat like a buttonhole; either
slit leads into a blind, pocket-like bag, inside the later mentioned covering piece v 1 ). None of the
enclosed skeletal pieces are naked.

In a specimen of the length of 29 cm , a breadth of I7 cm the following measures are found for
the appendix:

!) Petri 1. c. pi. XVI, fig. 4 gives a — neither good nor exact — figure of the appendix, seen from the dorsal side.

48

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

Length from the foremost end of the slit to the extremity . . 4o mm

— of the free part ij mm

The greatest breadth ca. io mm

The length of the terminal part 15™"

In another specimen of the same length and a breadth of 19™ the appendages were a little
shorter and broader, bnt otherwise as fully developed.

The skeleton. Between the basale and the appendix-
stem are found two pieces b z , 6 2 , of which the former is the
shorter one (seen dorsally it is much shorter), and bears the two
hindmost rays (the last but one is partly borne by the basale
also). The piece jit is long, longer than b 2 , flat; proximally it
articulates with b z , runs along b, without touching it, and arti-
culates distally by an oblique articulation with the appendix-stem 1 )-
The appendix-stem is rather straight, calcified in the sur-
face until the terminal part, where the mosaic of the surface sud-
denly ceases, and the outermost part of the stem is soft, which
soft part, chiefly of the same breadth as the harder one, thus
corresponds to the style, and reaches to the end of the terminal
part, ending with a broadly rounded, convex edge.

The marginal cartilages are both calcified, but very un-
equally developed, by which the whole appendix gets a peculiar asymmetric appearance; the ventral
one 2 ) reaches a trifle longer forward than the dorsal one, but backward it ceases far before this latter;
the dorsal cartilage is by a longitudinal furrow apparently divided into two pieces of which the lateral
one begins forward about the middle of the ventral cartilage, and stretches backward about as far
past the hinder end of this latter (see fig. 30, 31); this part of the dorsal marginal cartilage is on the
ventral side hollowed in a trough- or groove-like manner; the medial part of this cartilage, especially
the foremost part of it, is slightly calcified, membranous, and is placed like a cover over the appen-
dix-slit, so that a narrow slit is left between its outer edge and the ventral marginal cartilage.

Fig. 19.

Fig. 20.

P*ig. 19. Torpedo marmorata. Part of
the skeleton of the right ventral, from
the ventral side, r the hindmost rays
partly cut off. Natural size.

Fig. 20. The same preparation from
the dorsal side.

*) Petri has quite misunderstood the relations of these skeletal pieces, and has upon the whole been very unlueky
in his explanation of the skeletal pieces in Torpedo. Already his beginning: « Das Skelet von Torpedo besitzt nur sehr ge-
ringe Ahnlichkeit mit dem der vorher beschriebenen Arten , promises nothing good; and his description of the terminal
parts shows that he has not understood them at all. He has correctly seen that between the basale and the appendix are
situated two pieces: fig. 4D, b\ 6", but their length and position is given less correctly in the figure, which is, like all his
figures, rather bad; but then he has completely overlooked the piece ji as a separate skeletal part taking it to be a process
on the appendix-stem: Nach vorne entsendet dasselbe (i.e. the appendix-stem) an der medialen (i. e. the dorsal) Seite neben
dem zweiten uud dritten Glied des Basale entlang einen Processus, welcher mit dem ersten Basale am hintereu Elide uoch
in Verbindung steht . As a honiologou to the piece /J in Acanthias (Petri's fig. 5 r) he takes a little piece (fig. 4 D, r), which
is said to bear the two last rays and to have originated from a coalescing of the proximal joints of those: <es ist dieselbe
Concrescenz, wie ich sie bei Acanthias beschrieben habe . In Acanthias, however, the piece /9 [r in Petri) bears no rays,
as, after all, it never does. The little piece which Petri has seen in Torpedo (and in the figure marked r), is only an
1111 calcified corner of the basale itself, projecting over the two last rays, but it does not bear the rays.

2 ) The marginal cartilages are partly correctly seen and determined by Petri as < Riniienknorpel : Fig. 4 D and E,
c and /; F, /; (and pi. XVII, fig. 4 B, /); the skeletal piece, however, interpreted by Petri as a dorsal marginal cartilage and
marked /, is only the firm lateral part of the dorsal marginal cartilage; the thin, cover-shaped part seems to be removed,
except .hi fig.4 B, representing the muscles.

ON THE APPENDICES C.KNITAI.KS (CLASPERS) IN THE SELACHIANS. 49

The number of the terminal pieces is three; but to be able to see these pieces, and cor-
rectly to understand their relations to the marginal cartilages, it is necessary to remove a large
ventral covering piece, homologous with that mentioned in Rliina, and marked v, because the whole
ventral side of the terminal part is hidden as by the half of a thimble (the contour of which may
often be distinguished through the skin). The foremost edge of this covering piece is incised in an irre-
gularly heart-shaped manner, the one — lateral — corner being produced much farther than the other;
it is strongly rounded from side to side, and the surface is dotted with small holes. The edges of
this piece have on each side a peculiar bend, and immediately behind this the covering piece
is firmly joined to the specially thickened hinder edges of the two terminal pieces Td and Tv;
bv the said bends and the ventral concavities of the covered terminal pieces, the peculiar side-
slits and the walls of the before mentioned pockets* are formed. The M. dilatator is attached
to the fore edge of the covering piece, and by the firm connection between the covering piece
and the outermost point of the terminal pieces the action of the muscle is transmitted to
that point.

The dorsal terminal piece, Td, is quite short, somewhat convex towards the appendix-slit; the
ventral side on the contrary is deeply concave; together with the corresponding marginal cartilage
which, as we have seen, is also hollow, it forms a complete trough, in which the medial «pocket is
situated. The ventral terminal piece, Tv, has the double length, is likewise rounded on the dorsal side,
hollow on the ventral one, and forms with the covering piece the lateral -pocket. Finally a piece
T~ is added to the hindmost end of the ventral marginal cartilage, and to the proximal part of Tv;
it is shaped as a slightly bent, round thorn, almost hidden inside of the lateral edge of the cover-
ing piece 1 ).

The muscular system. The M. extensor is divided into two parts reminding of the state
in R/iiua. The foremost one originates from the foremost half of the basale, runs over the knee, and
is attached immediately below this to the M. dilatator, and partly to the distal end of ft and of the
appendix-stem; the hindmost one originates from the other, hindmost, half of the basale and from the
following pieces (also from ; S), passes with its distal part under (i.e. ventrally of) the foregoing one,
and is continued rather directlv in the medial part of the M. dilatator.

M. compressor. The bag-shaped part of this muscle, situated on the ventral side, is very small;
properlv speaking it is confined to a ventrally rounded swelling between the two hindmost rays and
the parts of the stem-skeleton, 5 Z and 6 2 ; accordingly there is no part projecting across the ray muscles,
the foremost contour of the bag being bordered by the skeleton (the pieces b l and b,), the outermost
one by the hindmost ray muscles. The ventral fibres of this little bag run obliquely backward towards
the hindmost ray, almost in continuation of the hindmost fibres of the M. adductor. The part form-
ing the outer lip-muscle, is rather powerful and long, originates forward from the piece /? (foremost

■) Petri, as already mentioned, is quite wrong as to the terminal part; he takes the dorsal terminal piece Td to
be the terminal joint of the appendix-stem (I.e. p. 308, fig. 4 F, & lv ); the ventral terminal piece and the thorn 7~ 3 become
zwei kleiue verkalkte Spaugen», borne by the hindmost part of the ventral marginal cartilage to which they are added
■ radienartig 1 fig. 4 E and D, sp" [= Tv], sp' [= 7j]). Only the piece v (fig. 4 E, F, D sch) has been tolerably correctly
described and interpreted by Petri. Thus he has had no idea of the homologies of the terminal pieces with those in Acan-
Ihias and Scy Ilium, not to speak of Raja.

The Ingolf-Expedition. II, 2. J

c ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

also from <5j, and the fibres pass obliquely backward towards the last ray and the ventral marginal
cartilage. On the inside of this latter the muscle continues somewhat farther back, tapering, and
with the fibres running straight backward. The whole muscular wall may pretty easily be separated
from the two hindmost rays to which its fibres are not really attached; when thus separated from the
rays the whole muscular bag shows a rather strong resemblance to M. compressor in Chinnrni.

The J/, dilatator is with the whole of its hindmost end attached to the covering piece v, and
thus, by means of the firm connections of this piece with the distal end of the terminal part, it acts
on the movable portions of the terminal part 1 ).

The glandular body is pigmented, and its longitudinal furrow runs a little obliquelv ; it
has before been briefly described by keydig 2 ) and by Petri (I.e. p. 22), but none of these authors
mention the peculiar fact, in comparison with the Raja-species (and accordingly it is to be supposed
that it has not before been seen), that the glandular body, continually tapering posteriorlv, stretches
throughout the shaft quite clown to the terminal part. In the shaft it follows the ventral mar-
ginal cartilage, and is here for some way along this skeletal piece surrounded by the outer lip-
muscle;, the latter appearing as the continuation of the dorsal muscular wall of the bag . The
longitudinal furrow, and the openings in it follow the glandular body quite to its hindmost end.

Torpedo oculata Belon.

In this species the features are principally as in T. niarmorata.

In a specimen of a length of 30°™, a breadth of ic/ m , the following measures were found:

Length of the appendix 43"

- - slit 36"

part free of the fin 17"

terminal part abt. 14"

Breadth of the appendix 7-

Tinin

-.mm

7 mm

4 mm

<mm

Narcine sp.

(PI. III. fig. 32, 34-)

A badly preserved specimen, the species of which is difficult to determine, measures in length
24,5 cm , in breadth i2 cm :

The appendix from the beginning of the slit to the hindmost point is ... . 27 mm

- free part 14"

- length of the terminal part io"

breadth of the — - 5 mm

■i Petri has given a very imperfect description of the muscles of which he only mentions M. dilatator. (Comp. 1. c.
fig. 4 B and C.)

2 ) Beitriige zur mikroskopischen Anatomic und Kntwickelungsgeschichte der Rochen und Haie, 1852, p. 86.

iinm

-.mm

ON THE APPENDICES GENITALES [CLASPERS) IX THE SELACHIANS. 51

The exterior of the appendix is chiefly as in Torpedo; we find here the same marginal slits
(and pockets I, but the medial one is with the buttonhole shaped, distal part situated quite on the
dorsal side, and the lateral one is turned a little ventrally; next it is to be
remarked that the appendix-slit in the whole of the free part of the organ is
King quite laterally, the dorsal lip overlapping it quite to the outer edge
like a cover, much broader than in Torpedo; corresponding to this the portion
of the terminal part containing the piece Td is folded quite over the hindmost -I — b,i

part of the appendix-slit. The glandular bag and its inner gland are relatively * A i

more strongly developed than in Torpedo.

Td

In the skeleton, notwithstanding the principal conformity with. Torpedo]

several peculiar features are found. Between the basale and the appendix-

Narcine sp. The right
stem also here two pieces, b t and o 2 , are found, the former short, the latter appendage from the

longer; b x bears the last rav at the connection with the basale; the last ray dorsal side. Natural

size. / the opening of
but one seems to me only to articulate with the basale. The piece /? is to- the medial pocket. Rd,

tallv wan tin?;. The appendix-stem is long- considerably longer than the ba- s-eea par co-

& l r & ' . & vered by the skm.

sale -|- b Y and b 2 ; it is calcified in the surface excepting the short end-style,

which distally becomes broad, flat, with rounded hindmost contour. The marginal cartilages are thin,
rather short, and occupy only the hindmost half of the stem; the ventral one shows the same features
as in Torpedo ; also here it reaches a little farther forward; the dorsal one, when seen from the dorsal
side, forms a broad, ovate leaf tapering proximally, and continuing as an uncalcified band quite to
the articulation of the appendix-stem with b 2 ; its lateral edge reaches to the free edge of the ventral
marginal cartilage; seen from the ventral side it is hollowed in a trough-like manner as in Torpedo;
but distally it does not nearly reach so far as in the latter, and consequently the two marginal car-
tilages do not end so obliquely of each other distally (this fact seems also to imply a greater mobility
of the terminal part in Narcine than in Torpedo).

The number of terminal pieces is three, to which is to be counted a quite similar ventral
covering piece v as that in Torpedo. As already mentioned, Td is folded to the dorsal side, and has
apparently a shape deviating considerably from that found in Torpedo; a closer examination shows
however that this deviation to some degree is due to the position; on the medial-dorsal side the piece
is hollowed in a groove-like manner (for the medial * marginal slit ■■); otherwise it is flatly rounded
on the outer surface, concave towards the appendix-slit, with a sharp lateral, convex edge.

Tv is short, oval, rounded towards the appendix-slit (as in Torpedo) concave on its outer sur-
face, by which, together with the covering piece z», it forms the hollow for the lateral «pocket». T~
is somewhat s-shaped, tapering to both ends, little and slender. The covering piece is chiefly as in
Torpedo; also here we find on both its margins curvatures destined (especially on the lateral margin)
to form the button-hole shaped opening of the pockets together with the terminal pieces Td and Tv.
The foremost lateral corner appears independent as a very small v'.

The muscular system is as in Torpedo with the exception that the part of the M. com-
pressor that may be seen on the ventral side, is relatively larger, and laterally spreads somewhat

52

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

more, and that the M. extensor is single. The glandular body is prolonged into the shaft quite as
in Torpedo.

Rhinobatidce.

Rhinobatus columnae Bonap.
(PI. Ill, fig. 35-370

In a specimen of the total length of 85,5™ and a breadth of 26™ across the pectorals the
appendix had a length of n,5 cm .
The other measures were:

from the fore end of the slit to the hindmost point of the appendix 7A cm

the part free of the fin 6,2 cm

Length of the terminal part i,9 cm

Breadth - - - o,8 cm

The appendix reminds of that in Torpedo, being flat, and having
(on the ventral side) the terminal part marked off by a slight constriction;
but it is considerably longer, with a long free portion, and a relatively
short terminal part, and so it has a rather slender, elegant appearance.
The ventral side is all covered with the same dense mosaic of fine, flat'
dermal teeth as the other parts of the belly; only the very outmost point
(i mm ) is naked and soft. On the dorsal side the region around the fore-
most part of the appendix-slit is naked as well as the whole part before
the slit, which is normally in contact with the belly, this having also a
corresponding naked spot; furthermore the naked part stretches as a
small stripe backward close to the medial edge until the terminal part,
the dorsal side of which is quite naked; otherwise the dorsal side is co-
vered with teeth , and has the darker colour of the back of the animal.
The appendix-slit is situated quite close to the lateral edge, only in the
terminal part it bends towards the middle. On the dorsal side of the
terminal part are seen two < marginal-slits > leading into pockets, quite
corresponding to those in Torpedo and Nardil e; the medial one is the
longer; in the lateral one the outermost part of the piece T, is seen freely
protruding from the skin as a shining thorn.

The skeleton. Between the basale and the appendix-slit are
found four pieces: b t , 6 2 , b i , b A \ the last one being the longest, next to that follows b l which is also
the broadest, but they are all more long than broad; b 3 and b 4 bear no rays, b 2 bears the last ray, b l
the last but one (and, in connection with the basale, also the last but two). The piece jl is exceed-
ingly long; anteriorly it articulates with the dorsal side of b l close to the basale, then it stretches

Fig. 22.

Rhinobatus columnar.
The left appendage from the
dorsal side. Natural size. F
the fin-membrane. /' the
opening of the lateral pocket,

/ of the medial one.

ON THE APPENDICES GENITALIS (CLASPERS) IN THE SELACHIANS. 53

along the other pieces, b z b. /;,, and next articulates with the appendix-stem b in a long joint, reaching
as far past the articulation of /; 4 , as the length of this piece b^ itself; it reaches quite to the dorsal
marginal cartilage. It is narrow and flat, distally a little bent. The appendix-skeleton is of a length
about equal to the basale + b t . . . b 4 , the stem is rather slender, and ends in a style of a similar
shape and nature as in Torpedo, only it is here relatively very short. The marginal cartilages are
very long; both of them begin almost at the same point forward, the ventral one, however, a little
before the dorsal one, and they end at the style in an inverse ratio, that is to say, the dorsal one
reaching a little farther backward. On the greater part of their external surface they are very closely
connected with the teeth-covered skin, so that they only with difficulty can be separated from it. The
distal part of the dorsal marginal cartilage is, quite as in Torpedo, ventrally hollowed in a trough-
like manner; this part is hard and firm, shining, while the other part is more soft, lamellar, lying
like a cover over the appendix-slit, and forward reaching to /?. The terminal part on the ventral side
is covered by a piece v, quite corresponding to that in Torpedo and Narcine\ the margins, however,
are without folds.

The number of real terminal pieces is three.

Td is very small, a little concave on its ventral side; Tv is larger, and bears on its lateral
edge a process directed forward; it is externally flatly rounded, internally towards the appendix-slit it
has a trough-like concavity. T, articulates with the hindmost lateral edge of Rv, and with the fore
end of Tv; proximally it is broadly ovate, and distally it tapers to a shining conical point, which, as
already mentioned, is uncovered by the skin.

The muscular system is principally as in Torpedo; the J fuse, extensor, however, is single,
as in Narcine. The glandular bag occupies here, as in those two genera, the space between the distal
end of the basale and the proximal end of the appendix-stem, but laterally it spreads over the hind-
most rays in a similar manner as in Raja.

The glandular body is very narrow, and does not anteriorly reach the end of the bag;
accordingly it fills the inner space of the bag to a far less extent than in the other Rays; it is pro-
longed as a thin, raised stripe, provided with a furrow and gland-pores as in Torpedo and Narcine,
throughout the length of the shaft till the terminal part.

Trygonidce.

Trygon violacea Bonap.
(PL III, fig. 38-40.1

A specimen of a length of i m , a breadth of 44 cm shows the following measures

The length of the whole appendix 9 cm

- free part 6,5

from the fore end of the slit to the hindmost point of the appendix 8'

The length of the terminal part 4'

The largest breadth at the base of the terminal part 1,5

era

«jcm

<cm

cm

54

ON THE APPENDICES GENITALES (CLASPERS) IX THE SELACHIANS.

\

v:

— -of

The whole appendix, as the ventral itself, is naked, somewhat latero-ventrally compressed, almost
triangular, when cut through, but with rounded edges; the broadest surface looks inward, and is in
contact with the base of the tail; the appendix-slit follows the more narrow dorsal side till the term-
inal part, where apparently it separates into two slits, surrounding a lengthened-oval, firm, and hard
part, covered by the skin (To); in reality, however, only the inner one of these slits is a continuation
of the appendix-slit (of); the outer one (/') leads into a deep « pocket ending far forward, and limited
by the terminal skeleton proper and the covering pieces to be mentioned later. Immediately before
the passing of the slit into the terminal part its inner (dorsal) lip forms a rather large, soft, pigment-
ed dermal fold, which, however, is not seen externally, being placed under the overlapping firm edge
of the outer lip, supported by the covering piece v.

None of the skeletal parts protrude through the skin.
The skeleton. Between the short basale and the appendix-
stem are found two pieces, b x and b 2 , of about equal length, but b l is
much the broader, especially proximally, where it is of the same breadth
as the basale, and where on its dorsal edge it articulates with a very
long piece ft, which, without touching b 2 , reaches to the appendix-stem,
and articulates with the dorsal side of this almost quite to the fore
end of the dorsal marginal cartilage. b 1 bears the last ray, which prox-
imally for a long way is coalesced with the last but one which articu-
lates with the end of the basale; these two are by ligaments firmly
connected with the ventral marginal cartilage. The appendix-stem is
long and powerful, more than twice as long as the basale -j- bj -\- b 2 \
its hindmost part (a little less than half the whole length) is uncalci-
fied as a strong, broad style reaching to or only a little past the end
of the terminal pieces. The marginal cartilages are both calcified, the
dorsal one most solidly; they reach about equally far forward, and
occupy almost the distal half of the stem above the style; behind the
dorsal marginal cartilage reaches a little farther than the ventral one;
the latter is concave on its outer surface , while the former is partly
rounded.
The number of terminal pieces is two, only Td and TV being found.

Td is a large, external!}' rounded plate of pointed-ovate contour, thickest at the medial edge
along the style, and laterally quite thin; the lateral edge is finely indented. To likewise is large, but
the inner surface, towards the appendix-slit, is rounded, while the outer surface is deeply hollow as a
trough, both edges of which are somewhat bent towards the concavity. The whole ventral side of
the terminal skeleton, as well as great part of the ventral marginal cartilage, is covered by two hard,
calcified, firmly connected covering pieces v and v t , to which the AI. dilatator is attached, and which
correspond to the single i< in the preceding genera of Kays (in Narcine, as we have seen, the proxi-
mal-lateral corner of v had already been partly separated as an independent piece, to which in Trygon
the larger piece z\ must be taken to correspond). The larger lateral piece ?\ shows distally a rather

Fig- 23.

Trygon violacea.
The left appendage from the
dorsal side; reduced. /' the open-
ing of the lateral pocket. V, Td,
Tv the parts of the skin, in which
the skeletal parts, indicated with
the corresponding letters, are in-
closed.

ON THE APPENDICES GKXITAI.I.S iCl.ASPERS) IN THE SELACHIANS. 55

deep hollow on the outer, otherwise rounded surface, by which means a strong ridge is produced on
the opposite, concave inner surface, and this ridge is firmly connected with the raised medial edge
of the piece To; the above mentioned deep lateral pocket is then situated between the last-men-
tioned pieces.

The muscular system is peculiar by the little marked bounding between the single groups
of muscles. Thus on the ventral side the fibres of the M. adductor are seen behind and medially to
continue, without any bounding whatever, directly into the M. dilatator, and laterally to pass over on
the M. compressor in such a way, that the contour of the glandular bag before and medially is quite
effaced; the fibres of the ventral wall of the glandular bag — as in Torpedo -- have the same direc-
tion as those of the M. adductor, and they are here, until close to the lateral edge, quite woven
together with the latter. On the dorsal side the marginal portion of the M. adductor is seen as a
powerful mass arising partly from the pelvis, partly from the aponeurotic covering of the muscles of
the abdominal wall, and laterally overlapping part of the M. extensor. This latter arises from the
whole extent of the basale, as well as from the following pieces, and is distally, without any bounding,
woven together with the M. adductor and the continuation of this, the M. dilatator, which latter also
with a considerable mass wraps the whole of the appendix-stem and both the marginal cartilages
quite to their margins at the appendix-slit. Behind it is attached to the proximal edge of the ventral
covering pieces (v , v T ). The part of the M. compressor, appearing as the outer lip-muscle, is only
sligthly developed; more developed is the part of the dorsal muscular wall of the glandular bag,
running more transversely, and wrapping the glandular body, which it follows throughout the shaft
to its hindmost end at the terminal part.

The glandular body stretches here -as in the preceding genera of Rays — through the
whole length of the shaft along the ventral marginal cartilage, constantly tapering backward, and
the furrow which in the part of the body, situated in the bag, runs from before obliquely to
the medial side (separating a pigmented and an unpigmented surface), continues with its pores
quite to the terminal part. The part of the appendix-slit situated in the terminal part, has quite
smooth walls.

The above described features of the glandular body, and several other characteristics — as for
inst. the presence of ventral covering pieces, enclosing a pocket with an opening through an outer
side-slit, and furthermore the hollowing of the ventral side of the piece To -- very much recall those
in Torpedo and Rhinobatus 1 ), and it is evident that Trygon is more closely allied to those than to
Raja, at all events with regard to the structure of the appendices.

Raj idee.

In this family the appendices reach to quite a considerable size, and consequently they, natur-
ally enough, have attracted the attention, and have in some species several times been the subject of
examination. As a rule, however, this examination has not been very thorough, nor has it been ex-

') Partly even those in Rhina.

56

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

tended to more species of the genus, and therefore the result as to comparison has only been slight.
The species show great differences that may easily be nsed diagnostically. The corresponding struc-
tures in the different species are easily pointed out; more difficult it is to work out the comparison
with the other Plagiostomes in a sure way. I hope, however, to have succeeded in this in the follow-
ing description of the species I have examined.

Raja batis L.

(PI. IV, fig. 45-43.)

The appendices of the Skate are mentioned by several authors, who, however, have restricted
themselves to brief remarks of the outer shape and the size. This latter may in old males be so con-
siderable that the appendices may convey a notion of Skates with three tails , or Skate-Kings»
(l'oiitoppidan) 1 ); Lillj eborg 2 ) gives, in old males, the length to be between T / 4 and r / 5 of the total
length of the animal, and says that the appendages reach far behind the middle of the tail. I know,
however, no thorough representation of these organs or their skeleton 3).

In a specimen of a length of i m 26 cm (2 ell Danish) the appendix has a length of 27,5 cm ■»).
The other measures were:

From the fore edge of the slit to the end of the appendix 25 — 26 cm

The part free of the ventral i8 cm

The terminal part I3 cm

The largest breadth (across the basis of the terminal part) 4 cm

The shape of the appendix is flattened, the contour clavate, the breadth increasing towards,
and culminating in, the big, ovate terminal part. The skin is naked in every place. The appendix-
slit in the free part of the organ is situated quite close to the lateral edge; in the part united with
the fin more towards the middle of the dorsal side; in front the slit is easily dilated, and a little-
finger may here be brought into the ventral glandular bag, the powerful gland of which may be
partly discerned through the skin; the rest of the slit until the terminal part is certainly open, but
on account of the stiffness of the marginal cartilages it can only be very little dilated; in the term-
inal part, however, dilation may easily take place, especially if the end of the appendix is bent ventro-
medially. In the terminal part the skin forms on the ventral side a large, soft lip, closing together
with the dorsal lip, which is supported by skeletal parts. If the soft lip is thrown back, its inner,
bluish-red mucous membrane is seen, as also a large skeletal piece (7* 3 ) with sharp, indented outer
edge; it is, however, quite covered by the mucous membrane, which on the dorsal side of the piece

1 1 See K r a y tr, 1. c. p. 993.
) 1. c. p. 590.

3) The Ray mentioned by Joannes Battarra in Atti dell' Ace. delle scieuze di Siena, Tomo IV, 1 771 , p. 553, the
appendix-skeleton of which he draws in fig. I, must be the Skate, or at all events a nearly allied species (according to Giglioli
[teste Lillj eborg] the Skate is not found on the coasts of Italy (?)). Davy I.e. p. 145 mentions the glandular bag and its
large glandular body, its secretion etc.

I In two skeletons of ventrals belonging to the Zoological Museum the appendices have a respective length of
A V " and 38cm.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

57

forms a great many transverse, soft, vascular folds (see fig. 24 in the text, />/). If the terminal part is
more opened, the walls of the appendix-slit are seen; they are very curiously formed, covered with a
mucous membrane, and their folds and pockets supported In-
different skeletal pieces. Besides what has been mentioned, we
find on the ventral side a firm fold with a porous edge, da,
reaching into the proximal part of the slit, and a process (7r' 2 ),
with a loose, soft covering, and supported by skeleton; laterally
of this process is found behind a deep recess or pocket, Lv. On
the dorsal side are seen two recesses, the foremost one (Ld)
very deep, and separated from the appendix-slit by a lamella
supported by skeleton; the hindmost one (Ld') is less deep; finally
is seen a process ( Tzi), enclosed in a soft membrane, which process
is laid against the above mentioned one on the ventral side of
the slit. The real continuation of the appendix-slit runs between
these two processes, as indicated by the sound in fig. 24 1 ).

The skeleton. Between the basale and the appendix-
stem are found two pieces , b 1 , b 2 , the latter longer than the
former; b t bears the six hindmost rays, b 2 , as usual, none; with
the dorsal and lateral edge of b z is connected a long, plate-shaped
/?, distally articulating with the appendix-stem b almost beside
the articulation between this latter and b 2 .

The appendix-stem is long, about twice as long as the
basale -\- b l 4- b 2 ; behind it becomes by and by dorso-ventrally
flattened, especially in the terminal part, where its outer end is
quite flattened, thin, and rounded. As is usually the case, the
calcification ceases in the terminal part; in the long part corres-
ponding to the style is however found on the medial edge a
strongly calcified region projecting in a somewhat bump-like
manner (x in fig. 45, 47). The marginal cartilages are long and
hard, and are for a long way rather closely joined with their
edges; distally they separate; the dorsal one begins before close
by the articular surface between [i and /;, but distally it does

not reach as far out on the stem as the ventral one, which in return does not reach so far proximally
as the dorsal one; thus an open space is found proximally, where the glandular bag joins in, and
where its foremost, dilatable outlet is situated. The dorsal marginal cartilage sends forth distally a

ITd 2 )

Fig. 24. Raja batis. The terminal part
of the right appendage, from the dorsal
side, strongly dilated (much reduced).
A sound goes through the bottom of the
appendix-slit, vl the soft, ventral dermal
lip; T^ the terminal piece T i covered by
mucous membrane with the dermal leaves
bl\ da a firm dermal fold, dotted with small
holes on the edge. Lv the ventral pocket,
Ld, Ld' the two dorsal pockets ; d, dl the
dorsal lip with the enclosed skeletal parts
d and Td 2 \ Rd' a dermal fold, supported
by a plate-shaped prolongation of the
dorsal marginal cartilage; Ti\ Tv 2 dermal
projections supported by the skeletal
parts marked with the same letters.

M In specimens with quite short, undeveloped appendices, shorter than, or of an equal length with, the fin-mem-
brane (the free part from 2,5 -3,5cm j n length), we, as might be expected, do not find much of these elaborate structures; in
such young appendices with all parts still soft the appendix-slit is easily opened and quite spread, and then the walls of
the slit are seen to be smooth and simple, upon the whole without recesses or folds, also in the terminal part; one strongly
pronounced dermal fold is however seen along the ventral lip; the inner, already plate-shaped edge of this fold represents
the spongy-porous dermal fold (da) in the adult, and in the lateral part of it the large skeletal part T 3 will develop.

The Ingolf-Expedition. II. 2. °

58

ON THE APPENDICES GENITALES (CLASPERS) IN THE SEEACHIANS.

long, triangular, plate-shaped prolongation, Rd, fig. 45, running into the terminal part, and supporting
the above-mentioned dermal fold.

The number of terminal pieces is five, and to these is to be counted a '-covering piece be-
longing to the aponeurosis of the Muse, dilatator. This covering piece 1 ) (fig 48) is chiefly situated
on the dorsal side, has a fairly triangular contour, flatly rounded, with part of the medial edge bent
in such a manner that it catches round the medial edge of the end-style (fig. 46, d). This piece quite
evidently belongs to the same kind of structures as those , described as covering pieces > in the be-
fore mentioned forms {R/uiia, Mas tc I us an tare tic us , Torpedo, Narcinc, Trygon), only the development
having here taken place in the dorsal side of the aponeurosis; and so I here (and in other Raja-
species) mark it with a d.

With the distal end of the dorsal marginal cartilage is only connected one piece, proximally
also touching the style; I regard it to be corresponding to the Td of the other Plagiostomes, as it is
situated in the same manner as that in the dorsal lip of the appendix-slit, and shows the same relations
to the marginal cartilage and the stem; it is rather thick, somewhat bent in a crescent-shaped manner
with the concavity towards the stem; distally it is firmly connected with the style of the stem by
means of an uncalcified (or slightly calcified) cartilaginous prolongation 2 ). With the hinder half of
the lateral edge of this piece Td is connected a long, narrow piece, attached by a band to the terminal
end of the style; it is situated in the edge of the dorsal lip, and I think it to be corresponding to
the piece, which in several other Plagiostomes I have called Td 2 . With the ventral marginal carti-
lage are terminally and laterally connected two pieces of a peculiar shape. Only the medial one of
these is also connected with the style of the stem, passing closely along it until the above mentioned
calcified bulb .r; this piece then must be corresponding to Tv\ it is rather thin, rounded on the outer
side, and prolonged to a slender, bent, obliquely-posteriorly and laterally directed part, ending in a
hook (it is this hook, which is seen covered by a loose, mucous membrane in the fig. 24 of the text
at Tzi). The other piece consists of a crescent-shaped, large part, the concave side of which is for a
long way connected with the terminal and lateral edge of the ventral marginal cartilage; most ante-
riorly the long horn of the crescent reaches into the appendix-slit; behind and laterally the piece is
prolonged to a long, rather slender process, tapering to a somewhat bent, flat part with a slightly
notched end (it is this process, which is seen covered by loose, soft membrane in the fig. 24 of the
text at Tv 2 ). I take this piece to be homologous with the fully developed piece Tv 2 in Spiuax (in
Acanthias and So/11 iiiosus it is only indicated), and its situation seems to me to settle this homology
beyond doubt. Finally is found, belonging to the ventral structures, a very large piece, rather crescent-
shaped when viewed from the ventral side, which must be corresponding to the piece T, (the thorn »
or spur- in different Sharks); proximallv it reaches far into the appendix-slit, is on its medial side
broad, flatly rounded, and sends forth laterally a high, sharply winglike ridge with undulating, finely
indented edge; somewhat above the middle it sends forth a tap-like process, ventrally overlapping
Tv z \ distally it ends with a plate resembling the blade of an axe, and ventrally reaching over the

') It is mentioned by the way by Moreau I.e. p. 251 under Raja clavata by the name of Cartilage interne > ; the
presence of Td 2 is also noted here, but this piece gets no special name, as it is not found in R. clavata.
-) This connection-piece I take to be not independent.

ON THE APPENDICES GENITAI.1-S (CLASPERS) IX THE SELACHIANS. 59

style 1 ) (to judge by the pieces before me this part seems to be a little varying- with regard to the
details of the processes).

As to the muscular system the reader is referred to Raja clavata with which the other
Ra/a-species agree exactly in most respects. The M. dilatator, however, is here somewhat more
distinctly than in the thorn-back separated into two, a large dorsal one, and a smaller ventral one.

The glandular body, as in all AV/7-species, is limited to the dorsal side of the ventral
bag proper, and accordingly does not continue into the shaft. In young specimens of the Skate with
undeveloped appendages not yet reaching the end of the ventral, the appearance of the gland is
rather deviating from that of the developed one; it is more flattened, and the gland-pores are spread
in more (four or more) rows over the greater part of the surface; in other words, it shows a rather
striking resemblance to the glandular body in Rhina. By a continued growth of the marginal por-
tions of the gland, and by a strong rounding of these portions, the surface that in younger animals
is provided with pores, will be hollowed, and thus apparently become more narrow, and in this way
the characteristic deep longitudinal furrow will arise.

Raja nidarosiensis Collett.

Of this species I have had only one pair of dried ventral skeletons, the appendix-part of which
had a length of abt. 33 cm . The principal features agree exactly with those of the Skate; the resem-
blance includes the common habit of the single skeletal pieces, but a closer examination of these will
show some minor peculiarities in the details; for inst. it will especially easily be seen that the piece
T z is bent in a somewhat different way, and has a relatively larger lateral wing, a larger forward
directed tap, and its distal end has not the peculiar shape like the blade of an axe; on its medial
surface it is deeply concave, spoon-like, etc. I shall however omit to give a detailed account of the
deviations of all the pieces from those in the Skate, and leave to others, who may have more material
at their disposal, to work out this subject more thoroughly; no doubt the deviations will make good
specific characters. According to the existing descriptions of the species the appendages are very
large, and are said to reach behind to the beginning of the first dorsal fin.

Raja clavata L.

(PL IV, fig. 49-52; Pl-Vl, fig.6 7 -6S.)

This Selachian I think to be the one whose appendices have most frequently been examined
and described. Duveruoy 2 ) has briefly mentioned them, their glandular bag with its glandular body
and their skeleton, the nomenclature of which he has formed in accordance with the appellations of
the parts of the hind limb and the foot of a mammal. Later they have been described by Vogt and
Pappenheim 5), whose description it is rather difficult to use on account of the want of references

J ) Iu my figure it has been displaced a little, so as to reach too far up on the other terminal part.

2) Cuvier: Lecons de l'anatomie comparee, 2d ed., vol. S, 1846, p. 305 (perhaps the description applies to R. circularise).

3) Rech. sur l'anat. comp. des organes de la generation chez les animaux vertebres. Ann. sc. nat. (Zool.), vol. XII,
1859, p. in — 117, pi. 3.

6o

OX THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

to the accompanying figures, and in these the total want of letters indicating the single parts; still
later they have been described by Petri 1 ) and Moreau 2 ). Besides short remarks on these organs
are found in several writers of mostly systematic works. None of these descriptions seem to me to
be quite serviceable.

In a specimen of the total length of 76"" the whole length of the appendix is i8 cm . The other
measures are:

Length of the free part i3 cm

from the fore end of the slit to the extremity of the appendix i5 cm

from the fore end of the terminal part ro cm

Largest breadth (across the base of the terminal part) . . 2j cm

The whole appendix is naked (but on the abdominal side of
the glandular bag are found some scattered thorns); the shape is
lengthened-elavate with a short shaft; the terminal part forms the club,
and is relatively very long, broadest at the base, and tapering from
thence towards the point. Only the foremost dilatable part of the
appendix-slit, the part forming the foremost outlet from the glandular
bag, is situated dorsally; from here the slit goes laterally, almost
even passing to the ventral side; from this side it can be seen, but
not at all from the dorsal side (contrary to the situation in the Skate).
This is brought about by the fact that the dorsal lip, which only
proximally is supported by skeletal parts, at the base of the terminal
part overlaps the slit to such a high degree; the ventral soft lip is,
when compared to that of the Skate, only very narrow. If the term-
inal part is opened so much, that the interior is seen 3), this latter will
present an appearance, apparently quite different from that in the
Skate; it will, however, be possible to point out quite corresponding
projections and hollows: on the ventral side of the slit is seen, rela-
tively only little conspicuous, the membrane-covered terminal piece T 3 ■»)
which shows before a sharp, cutting edge, and on closer examination
also is seen, as in Raja baits, to bear on its upper surface a row of
transverse, soft, but less developed dermal leaves bl\ a bayonet-
like, hard, and sharp-edged blade 5) (on which one may easily cut one-
self, although it is covered by membrane) projects strongly, correspond-
ing to Tv 2 in the Skate; to the piece Tv in this latter corresponds a

Raja clavata. The terminal part

of the right ventral appendage,

much dilated ; reduced. The letters

as in fig. 24.

') !• c p. 310.

2 ) Hist. nat. des Poissous de la France, vol. I, 1SS1, p. 248—259.

i) Petri, I.e. pi. XVI, fig. 1 D, has given a drawing of the dilated terminal part, which is quite unsatisfactory,
especially with regard to the ventral side.

4) Petri, 1. c. fig. 1 D, kk.

5) Petri, bj.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 61

long cylindrical process, reaching with the point into the ventral recess 1 ), which is here situated far
backward, almost terminally (/.r'); on the dorsal side are seen the two same recesses 2 ) as in the Skate,
but of different size and extent, as well as the projecting lamella Rd' 3) borne by the skeleton; the
only new thing that does not seem to be represented in the Skate, is a strongly projecting part sup-
ported by the skeleton, da*), which part belongs to the ventral side; it corresponds to the porons,
spongy, firm dermal fold in the Skate, where, however, no skeleton is found.

The Skeleton. Between the basale and the appendix-stem ( Metatarsien Moreau |Cuv.,
Duvernoy]) there is a <?, bearing the last six rays, a b z without rays, a flat /? with s-shaped edges,
proximally connected with b ly and distally by means of a joint with the appendix-stem 5). This latter
is about (scarcely) twice as long as B -j- b l -|~ b 2 , and closely behind the two proximal articular sur-
faces for b 2 and t 3 it becomes flattened, and ends with a quite flat, thin-edged, hindmost rounded part;
corresponding to the great length of the terminal part, the uncalcified style ( une sorte de phalange
Moreau [etc.]) forms the greater part (about two thirds; in my figure it is a little too short); also here
is found, about at the middle of the medial edge, a thickened and somewhat calcified part. The
marginal cartilages are large, plate-shaped; the dorsal one reaches farthest forward, but behind it
ceases much before the ventral one; the dorsal cartilage sends forth into the interspace between the
terminal pieces a long, firmly calcified, s-shaped and pointed, blade-like process, bent in an undulating
way, and with sharp edges (Rd\ fig. 50).

The terminal pieces are 5 (6), to which is still to be counted a covering piece 6 ). This (d) is
situated dorsally, is flatly rounded on the outer side, concave towards the terminal part, whose prox-
imal portion it covers; anteriorly it is curved in an oblique, half-moon-shaped manner, having the
lateral fore corner far drawn out; from this corner it shows an elevation running towards the medial
edge, and indicating the place of attachment of the M. dilatator; consequently the whole part before
this line is covered by the muscle. 7V?) has a broad line of attachment with the distal edge of the
dorsal marginal cartilage, but only touches the appendix-stem; outward it is somewhat flat, inward
concave; its lateral edge is convex, and somewhat indented; its distal end is attached to the appendix-
style by soft tissue, representing the cartilaginous bridge in the Skate. The piece Td 2 found in R.
bafis is wanting here. Tv is a long, slightly bent piece 8 ), provided with a short, hook-like point, and
having before a short articulation with the distal end of the ventral marginal cartilage, medially a
long connection with the appendix-style, reaching until the thickened and calcified place in this latter;
laterally it is for a rather long way connected with a bayonet-like Tv 2 9); this latter is connected with
the hindmost lateral edge of the ventral marginal cartilage by an oblique articulation , and distally it

1) Petri etc.
*) Petri a la, alp.
Petri pr.

4) Petri da.

5) Petri, fig. 1 C, 61 , i 2 , r \ Moreau (= Cuvier-Duvernoy): Tibia, astragale, calcaueum; basale r= femur.

6 ) Petri: sell' schuppenfSrmiger Knorpel , grossere Schuppenlamelle.; Moreau: Cartilage interne, no. 3, fig. 27,
1. c. p. 250.

7) Petri: sck, likewise schuppenf. Knorpel , kleinere Schuppenlamelle p. 3121; Moreau: Cartilage externe, 110.2.

8 ) Petri: si; Moreau: Cartilage no. 6 bis, cartilage en cuilleron.

9i Petri: 6f; ein bajonettahnliches , gedrehtes Knorpelstvick > (p. 313); Moreau: Cartilage en hallebarde (Du-
vernoy I, no. 6.

g 2 ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

runs out in an elegantly shaped, longitudinally somewhat twisted blade with a peculiar sharp lateral
edge. Ventrallv of this, and attached to the same edge of the ventral marginal cartilage, is found a
piece da' 1 ) which I do not find in the Skate, or in any of the other Plagiostomes I have examined,
but, according to Petri and Moreau, it evidently appears in several other Rqjd-species ; it has a
thick, lateral edge, and a rounded contour; it is movable and seems to be composed of two pieces, a
little, proximal, lamellar da\ and the larger distal da. Finally is found the large piece T s 2 ). It con-
sists of a more narrow foremost part, the proximal end of which is attached to the lateral edge of the
ventral marginal cartilage, and which laterally sends forth a sharp, winglike ridge (corresponding to
that in the Skate, but much lower), and next of a broader, hindmost part whose medial edge (corre-
sponding to the axe-blade in the Skate) folds round the appendix-styles).

The muscular system, with regard to the proximal part, shows the typical relations, as
will be sufficiently clear from the figures 67 and 68 on pi. VI.

The M. dilatator is on the dorsal side behind split into two parts, but this cleaving has not
been carried through to the proximal part of the muscle, and so the M. dilatator seems to me to
form one muscular mass here as well as in most of the other Plagiostomes I have examined. The
whole of the large dorsal part of this muscle is with its hinder end attached to the dorsal covering
piece, i. e. not to the edge of this piece, but some way in on its surface till a plainly indicated line
of insertion (see fig. 49 on pi. IV). In Raja batis the division of the HI. dilatator indicated in R. clavata
seems to be more strongly pronounced, and in other Raja-species •+) it even seems to lead to a separa-
tion into two independent muscles, one larger situated dorsally, and another smaller, ventral, which

') Petri: da em spatelformiger Knorpelstiick •■ (p.313); Moreau, who has correctly seen that it is composed of two
pieces, calls the little proximal one: Cartilage intermediaire, no. 4, the larger one: Cart, accessoire, 110.3.

2 ) Petri: hk < hakeuformiger Knorpel ; Moreau: (Duvernoy) Cartilage en soc de charrue, 110.7 (in the principal
figure, however, indicated by 1 ).

3) Vogt & Pappenheim's appellations have to be with difficulty found out from the description, this, as men-
tioned, having no references at all to the figures, and in these no letters are found. I give below the appellations of these
authors corresponding to my names. It seems that they have not clearly seen that the chief piece — la piece principale —
is composed of three parts; thev use the names la levre interne partly of the marginal cartilages, but without establishing
the independence of these pieces; the prolongation of the dorsal marginal cartilage is described (p. 1141 as ; une feuille mince
en forme de spatule . The other names are:

The covering piece d = piece externe, la plus superficielle (p. 115).
Td = piece externe; seconde piece.

Td = piece alongee, courbee en S; it is interpreted as coalesced of two pieces, the terminal part wrapping the appendix-
stem being called nine petite piece cartilagineuse formant une gouttiere etc. (this part in young animals is
possibly soft).
da = petite piece cartilagineuse .... presque carree et couverte .... par un coussin gelatineux.
Tv 2 = piece .... plus allongee, sa forme est semblable a celle d'une equerre tres large.
Tv = une derniere piece cylindrique etc. (p. 116).

41 For inst. in R. Schuttzii, according to Petri (I.e. p. 314; pi. XVII, fig. 2 B and C). Petri calls the greater,
medio-dorsal part M. levator, and thinks this part to be composed of two kinds of muscles, viz. the greater part of red
fibres in which is found a wedge-shaped -white part (fig. 2 B, a/) the fibres of which, however, are said to run — only
with altered colour — into the red mass (a difference of this nature I never saw in any Plagiostome); the smaller, dorsal
muscle is called M. rotator with regard to its action on the hakenformige Knoqiel (my piece 7" 3 ). In Raja clavata Vogt
& Pappenheim (1. c. p. 1 16), as it would seem, (the description is not quite clear to me) have also found two muscles where
I only find one; they speak of a Muscle ecarteur dorsal , originating on the large dorsal covering piece (where the fibres
"i their «M. releveur are said to be attached; according to their description this releveur for one thing is composed of
the dorsal layer coining from the body (i.e. the tail), and is rather incomprehensible to me); and next of a ' muscle ecarteur
ventral which by means of rather long tendons is attached to the outer side of the ■ s-shaped piece ( 7j). Duvernoy
also says (I.e. p. 308) that his Muscle grand abducteur - (M. dilatator) 111 la raie ronce» is divided in a similar manner, and
attached in the same way.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 63

latter during the dilation acts especially on the terminal piece A-, by which means this piece is turned
(revolving as the radius round the ulna in a human fore arm).

The J/, compressor (S) forms the bag situated on the ventral side; the direction of its fibres,
as far as seen on the ventral side, is exactly given on pi. VI, fig. 68; on the dorsal side (fig. 67) the
part forming the outer lip-mnscle, which part is rather small, is seen anteriorly arising from the piece /9,
and posteriorly attaching itself in the inner investment of the ventral marginal cartilage; when the
connective tissue laterally uniting it with the hindmost ray, is prepared away, it is here very distinctly
seen to be continuously connected with the dorsal muscular wall of the bag ').

The glandular body has by earlier authors been sufficiently described as well in this species
as in other AV/rt-species ; when developed it seems in all species to show principally the same
appearance.

Raja radiata Donovan.

iPl. IV. fig. 53—57-)
Brief remarks on the appendices of this species are found in several authors, as usually mostly
concerning the size 2 ) and the like facts. Lillj eborgs), however, not only says that they are very
large and in old individuals sometimes reach past the middle of the tail (in a specimen of the length
of 53 cm thev were i4 cm long and 3,2 cm broad on the middle), but he also gives a rather thorough de-
scription of their outer contour and whole shape; of the inner configuration of the appendix-slit he
only says that it is divided into parts or separate hollows ». He does not enter upon an examination
of the parts of the skeleton; he mentions only, that a piece in the dorsal lip has a free, backward
directed point. We find, however, in the older literature a representation of the skeletal parts of these
organs, as well as of their structure upon the whole, viz. by M. E. Bloch-*). His specimen had a
length of 16 inch, (about 42 cm ), and the appendices (from the pelvis) were 5 I / 2 inch, (abt i5 cm ) long,
1' - inch, (abt 3,5"") broad across the terminal part.

■I Petri has called this part of my M. compressor M. flexor pterygopodii biceps (I.e. fig. 2 B, flb\, and thereby in-
dicated that he thinks it to be corresponding to the muscle in Scyllium marked with the same name, which latter, however,
shows quite other relations (see my fig. 65 and 66 of Sc. slellare); he describes it as inserting itself on the dorsal marginal
cartilage instead of on the ventral one (this, perhaps, is only a miswriting). In the proximal part the Flexor plerygopodu
exterior of Petri corresponds to my M. adductor (A), his Flexor pt. interior to my M. extensor (E). The muscles men-
tioned by Duvernoy (in Cuvier's Lecons 2d ed. vol. 8, p. 307) are: 1) Le muscle abaisseur = my M. adductor; 3) L'abduc-
teur de l'appendice = M. extensor; 5) Le grand abducteur ou extenseur des pieces mobiles et terminates = M. dilatator; his
no. 2 le releveur de la nageoire > is the muscular layer coming from the body (pi. VI, fig. 67), and his no. 4 (Moreau's .court
extenseur 1 I am unable to unravel. The same names have mostly been used by Moreau (I.e. p. 255); his Muscle long
extenseur = M. extensor, his M. flechisseur = the part of M. compressor forming the outer lip-muscle. Moreau, in
correspondence with my opinion, describes his M. grand abducteur (M. dilatator} as separating into two bundles. Vogt &
Pappenheim, besides the already mentioned - ecarteurs > [M. dilatator) only mention the M. adductor as l'abaisseur de
l'appareil copulateur , and as the antagonist of this a releveur partly formed by the dorsal muscular layer coming from
the body. Bloch only mentions two muscles in Raja radiata (I.e. vol.6, 17S5) both together representing my M. dilatator.

-1 Kroyer 1. c. p. 943 gives the measures: a specimen 17 1 2 inch, long with appendices of the length of 4 1 2 inch.,
and thinks (p. 9541 that the appendages are very strongly developed in the adult males.

3) 1. c. p. 552.

4) Von den vermeinten doppelten Zeugungsgliederu der Rochen und Haie. Schr. d. Berl. Ges. naturf. Freunde, vol. 6,
: 7 8 5. P- 377- Bloch calls his Ray-species Raja clavata L, and in his faunal works he has drawn and described it as Raja
ctavata. The figures, 1. c. pi. IX, however, show with perfect certainty that the species in question is R. radiata. (Both this
plate and the one concerning Acanthias are, without any explanation, affixed to the edition by Schneider of Bloch's
Ichthyology.) Petri has not perceived that in Bloch the question is not of the real R. clavata.

6 4

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

Two pairs of ventrals with fully developed appendices, now before me (unfortunately I cannot
give the total length of the animals) show the following measures:

Length of the appendix io cm

- part free of the fin 6,2 cm

- terminal part 4,6 — 5™

Breadth of the

2,7 cm at the broadest spot

- basal part i,6 cm

A dried specimen of a length of 39"", a breadth of 24 cm shows full)- developed appendices,
8 cm long, and 2,2 cm broad across the terminal parts; in another specimen (in spirit) 43 cm long, and 2o, cm
broad the appendices are only 6,5 cm long, the terminal part abt. 4 cni long, 2,i cm broad; here thev are
not yet fully developed though it was to be expected judging from the size of the animal. Facts as
these, that rather grown individuals have rather undeveloped appendices, I have ofteuer seen, for inst.
in Acanthias.

The appendix is naked, much more clumsy than in the
preceding species, flattened, somewhat rounded on the dorsal side,
the contour is clumsily clubshaped; the club is formed by the
terminal part constituting more than half the length of the part
to be seen from the back. The appendix-slit runs from the fore-
most dorsal opening laterally, so that it cannot be seen from the
dorsal side except in the hindmost end of the terminal part,
where the dorsal lip, as it were, retires; the dorsal lip, throughout
the terminal part, is supported by inner skeletal parts reaching
to its edge, while the soft membrane of the ventral lip as a broad
wall stretches past its skeletal part (7" 1 ,), and is laid - in a
similar manner as in the Skate - - dorsally against the upper
lip; from the hinder, lateral edge of this latter a naked spine
projects. If the soft, ventral dermal lip vl is thrown back, an
elevated, long, bowshaped, cutting edge of the skeletal piece 7",
is laid bare (fig. 26 in the text, to the right of 61). If the term-
inal parts are opened still more (which here is easily done), we
shall, although with altered shapes and relations, see correspond-
ing projections and hollows as those described in R. batis and
clavata. The upper side of the piece T, does not here show (or
shows at most weak traces of) the transverse folds 61, peculiar in those two species; a broadly tongue-
shaped, rather soft and movable lamella with porous edge and spongy lateral surface represents
da in the Skate and the Thorn-back; a large, ovate, hard swelling corresponds to the process Tv 2 ;
behind and laterally of this the ventral recess Lv is found, large and deep; the foremost recess Ld is
smaller and more hidden, situated before the ovate swelling, and also the lamella Rd' supporting its
lateral wall, is only little conspicuous.

-da
- T,

vl

bl

To,

Lv

Fig. 26.

Raja radiata. The terminal part of the
right ventral, much dilated; reduced. Td 2
the naked spine of this same skeletal
piece. The letters as in fig. 24 and 25.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 65

The skeleton. Between the basale 1 ) and the appendix-stem, as in all AV/y-species, are found
a /', , a A, and a j8 2 ); A also here bears the last six rays. The appendix-stem is about twice as long
as B + /', -f 6 2 , flattened especially distally; its terminal part, being as usual uuealcified, here forms
an s-shaped , quite thin , flat style broadening towards the end. As in the other Ra/a-species the
dorsal marginal cartilage stretches forward almost to the beginning of the stem, but backward not so
far as the ventral one; this latter, especially distally, is a good deal broader. To the inner side. of
the dorsal marginal cartilage, at its distal edge, is articulajted a triangular cartilage Rd' (fig. 56); it
is quite corresponding to the one marked Rd' in the two other Aff/tf-species , in which, however, it is
only a direct prolongation, a process, from the marginal cartilage itself.

The number of terminal pieces is five, exclusive of the covering pieces. Three covering pieces
</,, d 2 , d 3 are found on the dorsal side. The lateral one, d t , is a good-sized, externally rounded
plate, with a bow-shaped, convex lateral edge folding round to the ventral side. Its medial edge is
rather straight and firmly connected with d 2 , which latter as a narrow band runs obliquely across the
terminal part, and tapers towards the medial end that is bent round to the ventral side, and by a liga-
ment attached to the point of the piece T 3 (see fig. 55). The third covering piece , d 3 , is connected
with the lateral end of the preceding one; it is of a triangular, externally somewhat rounded shape,
and by a ligament attached to the hindmost end of the appendix-style; with its inner surface is is
connected with the dorsal side of the piece Td 2 . The three mentioned covering pieces have all arisen
from the same aponeurosis of the M. dilatator, and accordingly they together represent the single
covering piece d in the Skate and the Thorn-back.

Of real terminal pieces two are found in the dorsal lip: Td and Td, (see fig. 54, 55). Td is
short; it is with its whole fore edge attached to the dorsal marginal cartilage, with its foremost
medial corner also to the appendix-stem; from its medial-distal corner it sends forth a soft, cartilagi-
nous part which farther backward is coalesced with the style (comp. the Skate); else its distal edge
is connected with 7V 2 , a proximally broad, distally narrow and tapering, very hard, somewhat s-shaped
cartilage; it is outwardly rounded, inwardly concave, and ends in the above mentioned thorn projecting
naked from under the edge of the dorsal lip.

To the ventral side belong three terminal pieces: Tv, Tv 2 , and T. The two first of these
are very peculiar, and can only be rightly seen when the skeletal parts are disunited (see fig. 57).

Tv consists of two parts, a body and a long process; the body is proximally attached to
the edge of the ventral marginal cartilage, with one edge to the medial edge of the style (see fig. 54),
and with the opposite one to the piece Tv 2 ; from the ventral surface of the body the process arises,
and forms together with the «body a kind of T; this process is bent in an irregularly s-shaped manner,
ends in a fine, hook-shaped thorn, and is situated in the deep, spoonlike hollow formed by the piece Tv 2 .

Tv 2 is still more peculiar; its chief part forms an oval spoon, outwardly strongly rounded, in-
wardly very deeply hollowed , from the foremost part of which a large, half-moon-shaped part arises join-
ing the inside of the ventral marginal cartilage of the appendix-stem; the lateral edge of the spoon»
is prolonged into a not quite calcified, winglike process; between this process, the half-moon-shaped

■) Bloch 1. c: < der erste Knochen des Sehenkels , fig. 1, /.

2) i, =^ der zweite . 6 2 = der dritte , ,3 = der vierte Knochen des Sehenkels , fig. 1, m, 11, o in Bloch .

The Ingolf-Expedition. II, _■. 9

66

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

part, and the firm body of the spoon part of the terminal piece 7", is intercalated as a kind of ar-
ticular head (see fig. 55).

This latter, T 3 , is large, forms a half-moon-shaped plate (fig. 55), the distal horn of
which is bent in a somewhat hook-shaped manner; the proximal horn stretches in between the mar-
ginal cartilages, far forward in the appendix-slit; on the concave edge of the half-moon the mentioned
articular head r ) projects bearing a large, transverse-oblong articular surface ; the upper or inner
surface (the surface towards the appendix-slit) bears at the lateral, convex edge a thin, bent, sharp
ridge which in some individuals is undulating or finely indented; it is the above mentioned edge
seen on the undamaged organ').

Still has to be mentioned a peculiarly elevated, round, narrow cartilaginous ridge x, running
across the dorsal surface of the appendix-style; this ridge seems to me only to be a special swelling
of the style, and to correspond to the calcified and thickened bump x in R. batis and clcevata.

Raja fyllae Ltk.

In a specimen j) of a total length of 55 cm , a breadth of 30,5 cm , the fully developed appendices
are n cm long, i.e. exactly 1 / 5 of the total length.
The other measures were:

-cm

-cm

From the beginning of the slit to the end of the appendix .... c/ m

The part free of the fin 7,6™

The length of the terminal part 5i5 cm

The breadth across the shaft i,5 c

the terminal part 1,75°

As in the other Raja- the appendix is naked. The outer form as well as the inner configura-
tion of the appendix-slit in the terminal part is very much like that of the Skate. The contour con-
sequently is of a more slender club-shape than in R. clavata or radiata with a longer shaft and a
pointed-ovate, somewhat broader club constituting the larger, hinder portion of the terminal part. As
in the Skate the appendix-slit can be seen for its whole length from the dorsal side, but runs close

M This evidently corresponds to the tap on the piece T~ in the Skate, which overlaps the piece Tv 2 .
I Bloch I.e. pi. IX has drawn most of these terminal pieces in a very recognizable manner, some of them even
excellently las fig. 4 and fig. 5). He distinguishes between an upper part (the chief piece of the appendix), and a nether part
(the terminal part); the first he interprets as a tibia with its fibula (?) ( ein Rohrenknoeheu , und sitzet letzterer oberwarts,
wie bey anderen Thieren , an dem Schienbein fest 1; this latter is = my dorsal marginal cartilage; I.e. fig. 1 and 3, q\ the
tibia again consists of: a piece (= my ventral marginal cartilage), 1. c. fig. 1 and 3, r, /-, welcher unter gewissen Umstanden
die Rinne verschliest . and of an unterer Knorpel ■ (= my appendix-stem), fig. 3, s\ it ends hooklike; this is brought about
by .the fact that Bloch has not separated the covering piece d } from its connection with the stvle. Bloch makes the nether
part consist of five pieces, which number arises from the fact that twice he makes two pieces one. These five pieces have the
following relations to my appellations:

Tj = fig. 4, der Sichel .
Tv 2 = - 5, der Helm .
Tv — - 6, der wurmformige Knocheu .
Td 4- Td 2 = - 7, der Winkelhaken .
o\ + d 2 = - S, die Schaufel >.
3) Station 25, at a depth of 5S2 fathoms; the Davis Strait.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 67

to the lateral edge; the dorsal lip of the terminal part, also like that of the Skate, is along the whole
lateral edge supported by skeletal parts, while the ventral lip has a broad, soft edge covering the
skeletal parts ( 7\), and passing round to the dorsal side; if this dermal lip is thrown back, we shall
sex-, quite as in R. baits, a naked, cutting edge of a raised, winglike ridge on 7',, running almost
throughout the terminal part. If this latter is opened still more, an almost complete conformity with
the features in the Skate will be seen; and thus it will be sufficient to point out the deviations.
These deviations are confined to the ventral side, and are chiefly as follows: 1) the membrane cover-
ing the inner, dorsal surface of the piece T 3 medially of the cutting edge, has very few and long,
obliquely situated, low dermal folds (that may easily be overlooked); 2) the fold da is shorter (short-
ened distally), softer, in the middle of its distal part it projects in a more tongue-shaped manner, upon
the whole most like that in A'. radiata\ it is as in this and in batis without any inner skeletal support;
3) the two projections corresponding to the skeletal parts Tv and Tv 2 , are somewhat longer, so that
the} - stretch distally over the opening of the ventral recess which thereby gets a somewhat other
appearance than in R. batis.

Raja circularis Couch.
(Pl. in, fig. 41-44.)

In old males the appendices are said to be somewhat more than '/=, of the total length; in a
male of a length of 79,2"", a breadth of 48,5°™ they were i6,5 cm long 1 ).

I have only had the occasion to examine a dried skeleton in the Zoological Museum; this
skeleton measures from the snout to the point of the tail 4o cm , across the pectorals c. 20 cm ; the appen-
dix-stem has a length of 6,5 cm , the terminal part of 3,7°", and a breadth of i cm on the broadest spot.
Between the basale and the appendix two pieces are found: b l bearing the 8 (7) hindmost rays, and a
longer b 2 , without rays, as well as a long, plate-shaped /?, broadest in the fore part.

The ratio between the length of the appendix-stem and B -f 6 S -f b 2 is 3/ a ; the rather narrow,
flat, soft terminal part is shorter than the calcified one. The dorsal marginal cartilage reaches forward
almost to the beginning of the stem, and ceases behind with a concave, oblique edge, the lateral
comer of which is situated much farther forward than the hindmost end of the ventral marginal
cartilage, which, as usual, does not reach so far forward. As in Raja batis and clavata, the dorsal
marginal cartilage sends forth a long, thin, pointed, lamellar (calcified) prolongation passing in between
the terminal pieces (it is not seen in an)- of my figures).

The number of terminal pieces is five, besides two dorsal covering pieces. One of these latter,
d 2 , I suppose to be corresponding to the piece that in R. radiata has been marked in the same way;
it is long and narrow, spreads distally in a spoonlike manner, and the medial edge of the broader
part folds round the appendix-style towards the ventral side, where it is attached to the distal end
of the piece T 3 (see fig. 43). The other covering piece, d 3 , is firmly connected with the dorsal surface
of the terminal piece Td 2 (as is also the corresponding one in R. radiata) and is (as in this) distally
closely connected with the end of the appendix-style; it is rather thin and flat.

x ) Malm, A. V: Goteborgs och Bohuslans Fauna, 1877, p. 906.

9*

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

On the dorsal side are found two real terminal pieces (see fig. 41, 42), Td and Td 2 . The former
is for a long way connected with the dorsal marginal cartilage and with the appendix-stem; from the
hinder end it sends forth a long, round, somewhat finger-shaped, bent process with rounded end, and
running obliquely towards the ventral side; on the dorsal side only a little of the basal part of this
process is seen, while a larger part may be seen from the ventral side (comp. fig. 44 Td). With the
outer hindmost corner of Td a piece Td 2 articulates, dividing behind into two branches, an inner one,
short and soft, attaching to the appendix-style, and an outer one, hard, compressed, produced to a
fine point (corresponding to the free thorn on the corresponding piece in R. radiata); this latter
branch is best seen from the ventral side (fig. 44, Td 2 ), as it is dorsally hidden by the covering
piece d v

The ventral lip shows three pieces: Tv, Tv 2 , and T y

Tv (fig. 42) is slender, anteriorly connected with the terminal end of the ventral marginal carti-
lage, which is folded round to the dorsal side; next it follows for a long way the appendix-style, then
folds ventrally round this as a rather thin prolongation (fig. 44), and ends finally with two small, diver-
ging points at the opposite edge of the style (comp. R. baits). This piece Tv is in its foremost part
laterally connected with the very large Tv 2 . This latter is somewhat half-moon-shaped, and is attached
with its foremost concave edge to the ventral marginal cartilage; it sends forth two processes; a short,
truncate one close to the medial edge, and laterally of this a long one, bent in the free end like a hook
(comp. R. latis\ the point of which is turned into the appendix-slit (dorsally); the piece Tv 2 , on its
inner side, towards the slit, is of a flat, spoonlike shape.

'/'. (fig. 43) is narrow, falcate, and its foremost end is situated under the lateral edge of Tv, in
the appendix-slit, between Tv 2 and Td; in its hindmost third part it bears on its medial, concave edge
a process corresponding to the articular head on T in R. radiata, but in the present species it
passes into a sharp, winglike edge stretching to the distal end of the piece; the lateral, convex edge of
T, is sharp and cutting.

Holocephala.

In the males of the Holocephales, as is well known, three particular organs are found that
are supposed to subserve the copulation, viz.: 1) the peculiar cephalic organ 1 ) provided with der-
mal teeth, 2) the pelvic appendages, i.e. the two organs placed in a ventrally open pouch on
each side before the ventrals, and whose skeleton is connected with the pelvis by an articulation; and
3) the ventral appendages. Only the two last-mentioned sets of organs, and especially the ventral
appendages, which correspond to those of the Plagiostomes, will be mentioned more thoroughly.

') This, however, is wanting in the genus Harriotla Goode & Bean, the appendices of which are also said to be
11 and simple ; of its pelvic appendages nothing is said (Oceanic Ichthvologv : Mem. Wus. Comp. Zool. Harvard Coll.
vol. XXII. (896, p 32).

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 69

Chimaera monstrosa L.

(PI. I, fig. 14. 15; pi- VI, fig. 69-71.)

The larger part of the appendix 1 ) is free of the fin, and the appearance consequently differs
rather much from that of the other Plagiostomes ; this free part is almost as long as the ventral fin
itself in its largest extent (from the point where the foremost part of the fin arises from the body, to
the end of the much produced lateral corner). The appendix may also here be divided in a shaft and
a terminal part; the shaft is thick, short, only about half the length of the terminal part; its inner
contour is straight, the outer one very convex, whereby the appendix gets some resemblance to the
part of the human leg below the knee, with a very prominent calf. On the dorsal side the appen-
dix-slit runs throughout the free part of the length of the shaft; anteriorly it begins already at the
connection with the ventral side of the body as a little roundish opening, the circumference of which
is partlv supported bv the inner skeleton, and consequently it is only anteriorly a little dilatable; from
this opening the slit, bent about in the same manner as the lateral contour of the shaft, runs to the
base of the terminal part, where it reaches close to the medial edge, and from here it passes on into
the terminal part along this edge. In front, behind the described hole, and posteriorly, where the
slit passes into the terminal part, its lips can only with difficulty, or not at all, be opened on account
of the stiff inner skeleton, but in the rather long interspace it is easily opened, as the lips are com-
posed of soft parts (muscles); in a specimen before me the two concerning, normally tight spots of
the slit are closed by the coalescing of the skin; in another specimen the case is the same, only to
a less extent, with the right appendix. The skin of the shaft is naked, smooth, thin, and slightly
pigmented, so that the muscles and their arrangement can be distinguished rather distinctly through it.

The long terminal part is composed of three branches 2 ) a medial one (£*) in immediate con-
tinuation of the straight medial edge of the stem; a dorsal one (6**), lying quite close to the lateral
edge of the foregoing, commonly only separated from it by the very narrow continuation of the appen-
dix-slit; in one single instance, however, I find the skin coalesced for a considerable part of this slit,
so that these two pieces only towards the point can be separated; finally a lateral branch (6***), rather
free of the other two. These three branches are generally of almost equal length ; sometimes the medial
one is a trifle longer than the others; they are stiff, and in their whole length supported by skeleton; the
medial one is covered with a fine, but firm, thin skin, through which the skeleton is seen very di-
stinctly; it is rounded on its inner, medial surface, and ends in a little, swollen knob; the lateral side
is flat, and pressed into a furrow in the skin of the dorsal branch. This latter branch and the lateral
one are more or less completely wrapped by a soft, loose, and tooth-covered skin, by which they are

'I The copulatory appendages have been described, more or less completely, by a rather large number of authors,
of whom I shall only mention: Gunnerus: Oni Hav-Katten, Det Throndhj. Selsk. Skr., 2, 1763, p. 299, pi. V— VI; Kroyer,
I.e. p. 79S seq. Lilljeborg, I.e. p. 51S; Dumeril, I.e. p. 681; Moreau, I.e. p. 463; the descriptions in Gegenbaur I.e.
p. 453, and v. David off I.e. p. 453 are very complete. Xojie of these authors mention the glandular bag.

-) In C/iim. collici Eenu. living in the Pacific Ocean (at the coast of California), the terminal part is said to have
only two branches (Dumeril I.e. p. 6Sr, Goode & Bean I.e. p. 32); Bashford Dean (Fishes living and fossil, 1895), gives
however, p. 107, fig. 116, a drawing showing three branches, the medial one of which is invested at the point with dermal
teeth, and besides by an articulation separated from the other part; this latter fact may perhaps be caused by an acci-
dental damage.

~ ( ix THE APPENDICES GENITALES (CLASPERSi IN THE SELACHIANS.

7 cm

T cm

rem

7 cm

rem

made thicker and, towards the end, enlarged in a clavate manner, when compared with the medial
one; the lateral branch in particular is often distally much swollen. The dermal teeth are fine, a little
bent thorns, all with the points forward, towards the base of the organ. The lateral branch does not
contribute to the bordering of the appendix-slit of the terminal part, this slit running only between
the medial and the dorsal branch 1 )-

In three specimens of the respective length of 78"", JJ cm , and jo cm , the measures were:

The length of the appendix from the fore edge of the cloaca 7,5 cm , 10,5"", 6,5 c,n

The free part of the shaft 2,3"", 2,6 cm , 2,3°

The terminal part 4,5 cm , 6 cm , 4,1°

The breadth (on the broadest part of the shaft) i,i cm , i,6 c "\ i,i c

The breadth (on the middle) of the terminal part o,7 cm , i,i c,n , o,7 c

The pelvic copulatory appendage has in all three specimens a length of . 2,i c

a breadth of o,6 cm .

In one pair of ventrals, kept in spirit, and skeletonized until the terminal part, belonging to a
specimen the total length of which I am not able to give, the appendix has had a length of more
than 9 cm , the terminal part of almost 6 cm by a breadth on the middle of i cm , at the end of i,5 cm ; the
skeletonized pelvic appendage is 2 cm long, and 1"" broad.

The skeleton. The pelvic arch is divided in the middle line, so that it is composed of a
right and a left piece; behind, dorsally above the articulation with the ventral, each of these pieces
is prolonged to a considerable process; on the foremost convex edge the peculiar, movable, foremost
eopulatory appendage , the Sageplatte (Gbr.) , is articulated ; the skeleton of this appendage is com-
posed of one piece, the medial edge of which bears a row of (5 — 7) large, crooked, finely pointed
dermal teeth; when in rest this piece is turned against the ventral surface of the pelvis which is
hollowed like a spoon, and then only the toothless edge laterally of the row of teeth is seen in the
opening of the pouch.

The fin-stem consists of a short, flat b as ale B bearing all the rays (the foremost broad mar-
ginal ray (R) is coalesced with it), a b z , a good-sized ft, and the appendix-stem b 2 ).

b 2 is not much shorter than the basale, with which it is connected in a rather movable joint;
on its medial side it is flat and broad, on the lateral side longitudinally concave; dorsally it forms a
narrow edge, forward produced into a large process _r, which by a lateral incision is made to form
the inner bordering of the above mentioned opening, with which the appendix-slit begins; the other
part of the dorsal edge of b x is somewhat laterally bent, and bears a rather firm margin of connective
tissue; the ventral edge is straight and rounded.

The piece /? is tolerably triangular, but with curved sides; it is much curved, and situated in

') In Ckimara affinis Cap. the appendices, according to Goode & Bean (I.e. pi. X, fig. 34, 35), are three-branched
trosa, I nit else they seem to differ rather much from those of this latter. The figures, however, are not distinct
enough to get a clear notion of the facts.

t In the figures of Gegenbaur I.e. pi. XVI, fig. 22, 23, and of v. D.avidoff, I.e. pl.XXIX, fig. 19, pi. XXVIII,

Kg. 3, 4, these skeletal pieces are marked in such a way that: b* = i b Gbr ' , 8 = [''' G '"'' , b = f 6l Gbr '

[c D. U 3 D. I d D.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS ji

such a way, that its concave side like a roof covers the lateral edge of the piece b t \ with its hind-
most corner it is by means of tight connective tissue attached to the lateral surface of this piece; its
medial edge is free, and forms the limit of the tight foremost part of the appendix-slit, as it also,
together with the process x of the piece £,, contributes to the bordering of the aperture, in which the
slit opens anteriorly. We find thus between Chimcera and most likely all the Holocephales (Callo-
rhynchus shows the same relations) on one side and the Plagiostomes on the other the great difference
that the appendix-slit anteriorly stretches over the piece j3, and on the dorsal side separates this piece
from the other parts of the stem skeleton.

The appendix-stem h is joined to I>, by an only slightly movable articulation, and forms the
whole terminal skeleton; no secondary cartilages are found, and consequently the terminal part cannot
he directly homologized with that in the Plagiostomes. The part of the appendix-stem lying in the
shaft, is short, medially flattened; its medial surface is continued directly in the prolongation forming
the medial branch of the terminal part; in the lateral surface is found a furrow-shaped hollow contin-
uing the furrow in b T ; both edges of this furrow are elevated and bent towards the concavity, what
especially applies to the ventral edge, which rises very much, bends quite over on the dorsal side,
folding over the edge of this latter, and lying close to the medial continuation, following this latter
quite to the end as the skeleton of the dorsal branch of the terminal part; laterally it forms the car-
tilaginous prolongation supporting the lateral branch of the terminal part.

That the cartilage of the medial branch of the terminal part is homologous with that part of
the appendix-stem, which in the Plagiostomes I have called the end-style, is an obvious conclusion,
and admits of no doubt. At a first glance it seems also obvious that the plate-shaped, folded ventral
edge with the two other branches must be corresponding to the ventral marginal cartilage in the
Plagiostomes, which latter frequently in Sharks recalls it by the plate that is bent in a similar
manner; it might even be tempting to continue, and take the two branches, the dorsal one and the
lateral one, to represent two terminal pieces (resp. Tv and T 3 ) coalesced with the ventral marginal
cartilage; or it might be supposed that this part of the skeleton in Chimcsra was representing a stage
where the terminal pieces had not yet been articulated off as independent parts 1 ). But a closer exa-
mination shows that the idea of these homologies must be dismissed; the folded ventral edge with
its two prolongations is in Chimmra absolutely one with the other appendix-stem, consists like this of
the same kind of hyaline cartilage, which is corroborated by a transverse section; as a homologon of
this structure in Chimara the question can only be of the more or less distinct ventral bordering ridge
on the appendix-stem in the Plagiostomes, bearing and continuing the ventral marginal cartilage (see
for inst the Greenland Shark). In the firm, liplike edge of connective tissue, which in Cliimcrra follows
the dorsal cartilaginous edge of the appendix-slit, an indication is found that may possibly be regarded
as homologous with the dorsal marginal cartilage in the Plagiostomes.

The muscular system. I shall only here describe the muscles that are of importance with

■) This has also been intimated by Gegenbaur I.e. p. 455; at the same place he intimates that his supposition that
the terminal pieces in the Sharks are transformed rays may possibly be wrong, since in C/iimczra the branches are in contin-
uous connection with part of the stem-skeleton.

_, ON THE APPENDICES GENITAEES (CLASPERS) IN THE SELACHIANS.

/-

regard to a comparison with those mentioned in the Plagiostomes as belonging to the appendix; as
to the other mnseles I may refer to the thorough description by v. Davidoff (I.e. p. 473 seq.).

Between the two halves of the pelvis a broad band (fig. 69— 71, s) is stretched, which, as it
were, supplements the hinder surface of the pelvis; anteriorly this band is attached along the whole
concave posterior edge of the pelvic arch, and laterally it reaches almost to the articulation between
the pelvis and the basale; in the median line it is somewhat thickened as a firmer tendinous stripe.
From the whole ventral surface of this band as well as from the ventral surface of the pelvis arises
the ventral layer 1 ) of the group of muscles representing the M. adductor (et depressor) pinntv in the
Plagiostomes; in the middle line a stripe broadening somewhat backward, is left uncovered (see fig. 70).
This muscular layer is composed of bundles that are distinctly seen distally. Of the medial and hind-
most fibres of this layer only the deepest-lying are attached to the ventral side of the basale, to the
thickened medial edge of this piece, from which edge the ventral ray-muscles (Ra, fig. 70) arise; other-
wise the greater portion of the medial fibres of this muscular layer is attached to these ray-muscles
until a line of insertion , distinctly seen in fig. 70. The foremost and lateral parts of this muscular
layer pass, without any bordering -- neither in the depth — , into the ventral ray-muscles, as is also
the case in the Plagiostomes 2 ). The other muscular mass 3) which together with the foregoing one
forms the M. adductor in the Plagiostomes (fig. 69, 71, A), arises from the dorsal side of the above
mentioned tendinous band, as well as from part of the dorsal surface of the pelvis (viz. until the
slight crest that separates it from the muscle m of the pelvic appendage); this layer is thicker than
the ventral one , and attaches to the thickened medial edge of the basale and to the piece b t , espe-
cially with a powerful portion of fibres to the large process x of this latter piece; 011 the ventral
side it reaches to the muscle D, which corresponds to the M. dilatator, and will be more particularlv
mentioned hereafter. A special ]\F. extensor has not been separated.

A far as I am able to see, only two+) muscles are found 011 the appendix-shaft, one corre-
sponding to the M. dilatator (D) in the Plagiostomes, the other to the muscular investment of the
glandular bag (inclusive of the 1 outer lip-muscle ), M. compressor sacci (S).

The J/, dilatator arises anteriorly with its ventral portion from the hinder end of the basale,
but with its other parts only from the piece b l , at some distance from the articulation between this
piece and the basale. Almost all the fibres run straight from before backward; only on the ventral
side some of them bend laterally; they are attached on b close to the base of the lateral and medial
branches of the terminal part, and a few fibres go to the skin covering the skeleton; on the

'I Oberflachliche ventrale Schicht, ssv, fig. 16, 17, pi. XXIX, v. Davidoff.

-\ I find upon the whole that the difference as to the arrangement of the ventral part of the M. adductor in Chi-
mara and in the Plagiostomes is only in degree; in many of these latter (Scy/lium, Pris/lurus, the Rays), the superficial part
of the ventral layer of the M. adductor stretches quite over the ventral side of the basale and more or less out on the ray-
muscles, v. Davidoff describes this .ventral muscular laver in Cliiiuara as stretching considerably farther laterally on the
fin than is really the case; and his words (1. c. p, 474): Zum Basale hat er gar keine Beziehung etc., are not correct.

si The apelvico-basale Fasern of v. Davidoff, fig. 15. 17, Pb\ they do not, however, as he thinks, arise exclusively
from tin- pelvis.

M v. Davidoff, I.e. p. 4S0, counts three, which he moreover calls vollkommen gesondert , viz. a ■Flexor , an Ad-
ductor , and an Abductor ; in three specimens of Chimcera that I have examined, I have not been able to find a real se-
paration between the two first-named; but even if such a separation might appear, it will be of only slight importance with
regard to a comparison with the Plagiostomes (as surely also with regard to its functions); at all events, « Flexor + Adductor*
v. D. is = M. dilatator; the AMuctor of v. Davidoff is the muscle of the glandular bag.

ON THE APPENDICES GENITAU3S (CLASPERS) IN THE SELACHIANS. 73

dorsal side (fig. 69) the muscle stretches considerably farther backward than 011 the ventral side, rea-
ching to the spot, where the appendix-slit passes to the medial side.

The muscle of the glandular bag, M. compressor, arises from the lateral edge of the
piece ,? (see fig. 69), and is inserted on the lateral surface of the piece 6 Z , and on the appendix-stem,
as also on the folded ventral edge of this latter. The fibres seen on the ventral side (fig. 71), pass
from the edge of ,} round the calf , running obliquely or transversely, so that part of them is in-
serted perpendieularlv on the appendix-stem; those seen from the dorsal side, on the contrary, run
straight from before backward, and they form the lateral limit of the appendix-slit, and are attached
where the edge folded from the ventral side, is prolonged as the dorsal terminal branch (fig. 69). The
opposite, medial, lip of the appendix-slit is formed by the M. dilatator.

Into the described, very voluminous muscle the dermal fold representing the glandular bag in
the Plagiostomes , sinks from the dorsal side through the appendix-slit. This structure has here evi-
dently remained in a state of development as that, with which it begins in the Plagiostomes; by a
transverse section we see that the bag may in reality be called rudimentary, as it only fills very
little in comparison with the powerful wrapping muscular mass. If we imagine this invagination to
grow verv much forward and ventrally, we may get a structure resembling that in the Plagiostomes;
part of the bag will then be situated on the ventral surface of the fin itself, and the muscular coat-
ing will, as it were, be extended to a thinner wrapping layer, while the part keeping its position
along the outer edge of the slit, will retain its original appearance and become the lip-muscle . This
dermal bag, which in Chimcera is so small, and whose inner surface is quite smooth and shows no
special gland, can nevertheless give plenty of secretion; this fact is proved by the abundance of fluid,
partly filling the bag, partly adhering to the branches of the terminal part, and also filling the
corners between the base of the fin and the body; on the last-mentioned place it may be supposed
to have flown from the foremost, larger, roundish opening of the appendix-slit.

I have not a quite clear understanding of the influence of the muscles of the appendix-shaft on
the terminal part ; however, I think it likely that by a contemporaneous action of both the said muscles
a -- probably rather slight — distension of the three terminal branches may be brought about, the M.
dilatator acting on the medial branch, the M. compressor on the two others; by this action the con-
tinuation of the appendix-slit between the medial and the dorsal branch would be opened. That also
here the M. compressor will serve for the pressing out of the secretion of the glandular bag , seems
to me to admit of no doubt.

As to the pelvic appendage (fig. 70, 71,/), to which nothing corresponding is found in
the Plagiostomes, it is in Cliimcrra rather simple; its contour is tolerably spoon-shaped, and it bears
on the surface that in the position of rest is turned ventrally (but which will accordingly be turned
dorsally, when the organ is directed forward), a soft, loose, unpigmented or slightly pigmented dermal
cushion, while the membranous skin of the opposite surface fits tightly to the skeleton. For moving
this organ has only one muscle (fig. 69, w), by which it can be raised in such a way as to come out
of its pouch 1 ), when it is able to take hold with the toothed edge. This muscle is very powerful^

") Comp. also G arm an: On the Pelvis and External Sexual Organs of Selachians etc. Proc. Boston Soc. Nat. Hist.
Vol. 19, 1S76 — 78, p. 199.

The Ingolf-Expedition. II. 2.

74 ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

as it has no antagonist, the resistance of the surrounding skin, and, I think, also the pressure of the
abdominal muscles over the base of the pouch, must be regarded as the cause why the organ folds
back and is hidden in the pouch, when the muscle m is relaxed. The way in which this muscle is
attached, has been described more in detail by v. Davidoff (I.e. p. 479).

Callorhynchus antarcticus Lacep.

The appendices have been briefly mentioned by Dumeril (I.e. p. 6S1) as follows: «Ceux des

Callorhynques consistent en des prolongements cutanes, enroules de maniere a former uue paire

de cylindres creux et irreguliers que soutiennent des cartilages flexibles ; the foremost pair of organs,
which are enclosed in the pouch, and have here a far more complicated structure than in Chimcera,
have been more particularly described. The same organs have later been mentioned, though still
rather briefly, by T. Jeffery Parker, in a kind of preliminary note 1 ), in which is found the rather
bold hypothesis, that these anterior appendages* in Callorhynchus are representing a middle pair of
limbs , they being understood as serially homologous with the real appendices; thus Callorhynchus
(and the Chinucru- in general) should (but to be sure only in the males!) show the remains of a hexa-
pod stage . The real appendices ( posterior claspers ) are only mentioned with a few words to the effect
that they correspond to those in the Plagiostomes, as they occur in the same position, have the
form of a plate rolled longitudinally into a tube, and are supported by a prolongation of the basir
pterygium».

In a specimen (in the museum in Copenhagen) of a length of abt 70*™ I find the following
measures:

The length of the (real) appendix from the fore edge of the cloaca 8,5°

The length of the terminal part 5 cm

The breadth across the base of the shaft i,7 c

- middle of the terminal part 0,8 — 0,9°

As to the habitus the appendix at a first glance reminds more of that in the Sharks than of
that in Chiuncm; but a closer examination shows a very near relation to the latter; it is only the
terminal part not being split into branches, that causes the apparent resemblance to the Sharks; the
shaft corresponds in shape quite to that in Chimcera, and is, as in this latter, covered with a thin,
naked skin, through which the extension and form of the muscles may be distinctly discerned;
on the terminal part there are, as in Chimczra, no muscles at all; but here the skin is every where
thin, and is lying immediately over the skeleton, so that a reliable view may be got of the
structure of this skeleton unfortunately I could not skeletonize the only male specimen of the

museum. The terminal part is somewhat dorso-ventrally flattened with rather parallel sides, only
a little tapering towards the rounded end.

On the dorsal side the appendix-slit rnus as a narrow slit, beginning, as in Chimcrra, with a
rather large opening at the base, close to the abdomen; this hole* is supported by skeleton to the
same extent as in Chi 111 a- ret; from here the slit runs in a curve through the shaft into the terminal

'1 Notes from the Otago University Museum, VIII On the Claspers of Callorhynchus. Nature, vol.33, 1S86. p. 635.

-cm

-.cm

ON THE APPENDICES GENITAWBS iCLASPERS) IN THE SELACHIANS.

75

— (lb

h*-

Fig. 2S.

Fig. 27. Callorkynchus antarciicus. The right
ventral appendage from the ventral side; a little
reduced, ab abdominal pore.

Fig, 28. The same from the dorsal side.

part, where it passes over the medial edge on the ventral
side, and here it ends in the shape of an 5"; thus the
whole slit is formed like a cork-screw. Immediately be-
hind the hole the edges can only with difficulty be
separated on account of the stiffness of the skeleton; but
in the terminal part the slit is easily opened on account
of the thinness of the skeleton, which is here like a thin,
convoluted shaving, which may to a certain degree be
unrolled. The inner, tubular hollow of the terminal part,
as well as its opening at the point is completely stuffed
with secretion, which also fills the hole at the base as
well as the nooks between the appendix, the base of the
fin, and the body.

As to the skeleton, I think it pretty sure that
in the shaft it is as in Chimmra; as we find a rather mov-
able joint before the hole , the surroundings of which
seem to be quite as in C/iiiitcrra, we may be justified in
supposing the basale to end here; somewhat out on the
shaft we find another, little movable joint; accordingly
the piece b t is found between these two points; on the ventral side the distal border of this piece is
distinctly marked by the cessation of the inmost part of the muscular mass of the glandular bag (the
calf ); the other part of the skeleton then must be the appendix-stem; this seems here to be formed
like a convoluted leaf, in which no separation into branches is found; such branches, no doubt, would
be discernible through the membranous skin, if lines of separation really existed (the only place where
such a line of separation might perhaps be found, is along the lateral edge of the ventral side,
where a longitudinal furrow in the skin is found in both appendices, but I can find no mobility
along it, and take it therefore to be due only to the skin). If we imagine deep incisions in this carti-
laginous leaf, the three-branched form in Chimmra might arise; on the other hand we may from the
three branches in Chimmra (see pi. I, fig. 14, 15) easily reach the structure in Callorkynchus by "ima-
gining a coalescing on the dorsal side (fig. 14) of £** and &***, on the ventral side of b*** and b* (fig. 15).

The muscular system, with regard to the appendix-shaft, is evidently as in Chimmra;
M. dilatator (D) is easily recognised; its chief portion is situated dorsally (M. adductor v. David.), and
originates on b t while the inner and ventral portion (J/, flexor v. D.) also here arises farther forward
on the basale, and does not reach so far backward; further the large muscle (S) of the glandular
bag, which in no respects shows other relations than in Chimcera, with the only exception that is is
a little shortened veutrally.

The foremost copulatory organs, the pelvic appendages, are very remarkably formed, and
much larger than in Cliimcrra. The pouch in which they are hidden, is therefore also much larger;
the entrance of this pouch forms, when closed, a longitudinal slit (abt. 2,5 cm long), and is situated la-
terally, immediately before the ventral fin. The chief part of the organ enclosed in the pouch, corre-

7 6

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

sponds to the Sageplatte^- 1 ) of the Chii>urra\ it is here more lengthened, with a longer shaft' broad-
ening in the free end to an obliquely cut off, rather thick plate; this plate is on its (when in the
position of rest) ventral surface towards the edge invested with numerous, flat, sharp, comb-shaped
dermal teeth, of which those nearest the edge are the largest. Each tooth is almost fan-shaped with
the edge divided into 5 — 7 pointed comb-teeth, of which the middle one is the largest (comp. Dume-
ril I.e. pi. 14, fig. 2, 2 a). The teeth continue, somewhat smaller, along the whole (dorso-) medial edge
of the Sageplatte ; they are placed on a dermal lip, which is unsupported by skeleton (and borders
the afterwards mentioned canal, into which a sound can be introduced). As far as I can see the teeth
continue all the way to the attached base of the organ. The points of all these teeth are turned forward.
On the opposite surface (the dorsal one when in the position of rest) this Sageplatte is pro-
vided with a rather curiously elaborate system of large dermal folds partly supported by an inner car-
tilaginous skeleton 2 ). From the dorsal edge of the organ a large, folded dermal plate projects on
either side. 1) The lateral one of these plates somewhat recalls a human ear, and is with its free
edge folded towards the dorsal side of the serrated plate ; the proximal part of this membrane is
supported by a particular cartilage, while the distal part which is very much folded, has no inner
skeleton. 2) Next another dermal leaf arises from the dorsal and lateral surface of the serrated plate ,
opposite to the former; it is folded the other way, and situated between the serrated plate and
the first leaf; it has no skeleton. 3) The second dermal leaf projecting from the serrated plate»
towards the medial side, is anteriorly grown fast to the inner wall of the pouch; its free edge
is folded in such a manner, that it forms a kind of bag; it contains no skeleton, but where it
posteriorly is united with the lateral leaf (1) at the dorsal edge of the serrated plate , these two
leaves, by a rolling of their common hindmost part, form a tube supported by a stiff cartilaginous
skeleton; the free end of this skeleton projects some way past the end of the serrated plate > (cp. the
figure of Dumeril). A sound inserted into this tube, can be brought far into a deep, dorsally open
canal along the dorsal edge of the serrated plate ■ ; on the medial side the bordering of this canal is
formed by the above mentioned teeth-eovered dermal lip. 4) Finally a big, white, ovate body project-
ing from the medial wall of the pouch, is found outside the bag formed by the inner dermal leaf (3).
This evidently is a glandular body 3), the opening (or rather openings) of which seem to be inside
the bag formed by the inner leaf (3), in the foremost, inner corner of this bag. From this gland pro-
ceeds the very abundant secretion filling the space between the serrated plate and the described
elaborate dermal folds, as also the peculiar tube, evidently the excretory duct for this secretion. As

M As far as I have been able to determine without dissection, this part in the specimen in hand has a length of
ca. 3,5 CI ", a breadth of ca. 2«n across the broad terminal part.

2 ) Only the cartilaginous skeleton has been rendered — and scarcely quite completely — in the mentioned figure
liv Dumeril, as also this skeleton only is mentioned in the text (I.e. p. 682); this work, therefore, gives only a very iucom-
plete idea of the whole organ; the same may also be said of the short communication by Parker in Nature ; upon the
whole it is very difficult, without drawings and dissection, to give a tolerably clear survey of these complicated structures.

i] Parker evidently has also seen this glandular body: In connection with the sac is a gland secreting a lubricat-
ing fluid, and closely resembling the well-known gland of the Elasmobranch claspers* (which gland, however, is not found
in all Elasmobranchii). To this is added the interesting observation: In the female, although the clasper itself is absent, a
small glandular sac occurs in the corresponding position;. Garmau (I.e. p. 200) has, earlier than Parker, seen the gland,
and given a very short and incomplete description of the pelvic appendages. He thinks that the above described cartilagi-
nous tube serves for conducting the secretion into the groove of the penis (i. e. the appendix-slit), when it is turned forwards,
and through the latter the fluid is conveyed to the oviducts of the female >. The supposed turning forward of the appendix,

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 77

to the signification of this secretion as well as to the use of the whole organ we can only form rather
vague conjectures.

Of the mobility and muscular system of the pelvic appendage Parker gives the follow-
ing information, showing that the same muscle is found here as in Chimcera: The Clasper is exserted
bv the action of a strong muscle arising from the inner face of the pubic cartilage and passing over
its anterior border to be inserted into the principal cartilage (« the serrated plate ) of the clasper. The
plane of movement of the organ is nearly horizontal .

3. Which is the Function of the Appendices Genitales?

That the ventral appendages are peculiar to the males of the Chondropterygians is an old and
widely known fact — thev have already been mentioned by Aristotle 1 ), and at the present day most
fishermen distinguishes the male from the female by means of them 2 ). Everybody then agrees that
these organs in some ^vay or other subserves the copulation; but till recently we have had no real
observation of the copulation of Chondropterygians 3), and we have therefore been obliged to form
our opinion of the use of these organs from their structure. Many authors -- Rondel et-t), I think,
as the first — have thought the appendices only to be organs for clasping the female during copu-
lation, and therefore names as < Holders , Claspers .. , Haftorgane , Halteorgaue , Klammern , and
the like have been generally used; as a consequence of this idea they have always, I think, been
considered to act as a kind of prehensile organ, which might cling to some part of the body of the
female outside, and thus hold it fast 5 ). Others, on the contrary, have supposed that these organs
have to be introduced into the sexual organs of the female; but their action there has been inter-
preted in several ways. Almost all the earlier authors, as Linne, Artedi, Willughby (Ray),
Klein, Battarra, Gunnerus have thought that they convey the sperm, and called them Penes,
Mentulce, or Membra genitalia^ and with regard to their existing in pairs, some of those authors refer
to the Snakes, which analogon also seems to be rather obvious. After the appearance of the works
by Bloch, the first-mentioned idea of the appendages as mere external clasping organs gained many

however, cannot take place, and so the whole supposition has to be dropped. Gar man does not mention the structure of
the appendix itself.

: ) 'Ioroptac TZBfn Zi'iuiv. Ed. by Aubert and Wimmer. Leipzic 1S68, vol. I, p. 455. Chap. V, 5, §15.

2 ) Lorenzini (Osservazione intorno alle Torpedine, 167S), who, it would seem, has only known the appendages-
in the Rays, declares that they may be found in both sexes. He says nothing of their function. This misconception — that
they are also to be found in the females — recurs oftener. I think the assertion by A. Fritsch, that in the Xenacanths the
old females are also provided with appendages, to be not better founded. (In Bashford Dean: Fishes living and fossil
[Columbia Univ. Biol. Series, III] 1895, a figure is found on p. 73, representing -General Anatomy of shark (9)», and this 9 is
provided with claspers ! |,

3) The lively description by La Cepede iHistoire uaturelle des Poissons, T. I, p. 254— 55 1 of a copulation between
two Sharks, is evidently not founded on observation. His description and construction of the appendices (1. c. p. CXLHI, p. 70,
p. 273) are based on the essays of Bloch.

4| Libri de piscibus marinis, 1554, Lib. IIII, p. S9: Mares cartilaginei fere omnes circa podice appendices duas habent
quibus coire creduntur. At ego illas ssepe multumque contemplatus, non video quo pacto his coire illi possint: potius igitur
ad retinendas foemiuas factas esse arbitror .

5) This is decidedly said by Bloch (Schr. Berl. Ges. vol.6, pp.379. 384), whose excellent representation seems to
have influenced very many authors; further by Home (Phil. Tr. 1809, p. 207 , and 1S10, p. 206), by Cuvier & Valen-
ciennes (Hist. nat. des Poissons P. I, p. 536), by Treviranus (Tiedemann u. Treviranus Zeitschr. fur Physiologie vol.2,
1828, p. 9 [in the explanation of the figures]), by Dumeril il. c. p. 241), and others.

ON TIN'. APPENDICES GENITAI.ES (CLASPERS) IN THE SELACHIANS.

adherents, but the notion that they are real penes, i.e. organs conveying the semen, seems never to
have been fully superseded by it; Blainville advocates this opinion 1 ), and later we find it in Mayer 2 ),
in LeydigJ), Stannius-t), Steenstrups), L. Agassiz 6 ), Davy/), and (partly) Giiuther 8 ); this
opinion, after all, is perhaps to this day the most widely spread; it is also rather obvious, and analo-
gies from other groups of animals present themselves, as it were, spontaneously 9). This interpretation
of the appendages as the direct conveyers of the semen, however, meets with difficulties, which partly
have been correctly seen by several authors; some of those then have adhered to the opinion that
they are introduced into the cloaca of the female, but only to be more indirectly subserving the copu-
lation. Thus Geoffroy St. Hilaire 10 ) characterizes them as clitores, and Petri 11 ) thinks their chief

■I I.e. p. 126. Blainville promises a treatise on la structure et les usages de ces appendices dans les raies et les
squales , in which he even thinks to have found a connection with the sexual organs proper, what he had not been able to
do in le S quale pelerin .

2 ) TJber die Bedeutung der fussformigen Anhange bei Rochen und Hayen , und ihr Wiedervorkommen bei niederen
Thieren. Frorieps Notizen aus dem Geb. der Natur- und Heilkunde, vol.40, 1834, p. 273. Mayer supposes that these limbs
by the Mitscnli adductores are brought to the cloaca, receive the semen into the appendix-slit, and convey it on to the terminal
part, the opened leaves of which wie ein Blumenkelch embrace the cloaca of the female; further he imagines that the
copulating animals wahrscheinlich von einajider abgewendet sich befiuden (Petri 1. c. p. 291 reHders the description by M.,
but in more respects incorrectly).

;) 1. c. p. 86. Hie sogen anil ten Haftorgane erinnern in ihrer gewundenen, rinnenformigeu Gestalt sehr an die ausseren
Begattungsorgane maneher Krebse und ich glaube, dass sie ebenso wie diese zum Uberpflauzen des Samens nach den weib-
lichen Geschlechtstheilen dienen, wobei dann das Sekret der oben beschriebenen Driise eine vielleicht die Samenmasse ein-
hullende oder schiitzende Rolle spielt .

4) Handbuch der Anatomie der Wirbelthiere, 2 Aufl., 1S54, I, p. 278, note 5.

5) Hectocotyldannelsen hos Octopodslaegterne Argonauta og Tremoctopus. Kgl. D. Vid. Selsk. Skrifter, 1S56, p. 26.
«I think, however, .... the analogon to be as obvious, which is found in so many males among the decapod Crustacea, in
which a pair of the abdominal limbs are formed as more or less complete tubes, or the analogon, seen in the male Rays and
Sharks, where the ventrals, that is to say, active organs of motion, have one side transformed into large ducts of the semen.

6 ) 1) Proceedings of the Boston Society of Nat. Hist. Vol. VI, 1856—59, p. 377. 2) Ibid. Vol. XIV, 1871, p. 339. In
the first-mentioned place is only found a report of some observations by Agassiz occasioned by a lecture on the egg-devel-
opment in Rays; he thinks the claspers • of the Rays to be real copulatorv organs, supposing them to be turned forward
and upward, by which turning an opening in them (the larger basal opening of the appendix-slit?) is brought up to the
spermatic ducts ; it is supposed that they may easily be introduced into the oviduct even to the shell-gland. In the later
communication (2) this is more particularly worked out: One raj' of each posterior fin is capable of erection and rotation,
and is covered with erectile tissue, far too delicate to allow it to be used as a clasper around a body covered w-ith sharp
rough spines. In the act these two organs are rotated inward and forward, bringing the furrows on their inner surface into
parallel contact, and in apposition with the testes. Being then introduced into the body of the female, their extremities
diverge in the two oviducts, and the glans being uncovered exposes a sharp cutting instrument, which would injure the
organs of the female if she resisted ; the male has her, therefore, in complete subjection, and has been observed to strike and
wound her with this spine. What was formerly supposed to be the penis is too small, and of insufficient length to accom-
plish fecundation (viz. the urogenital papilla). The penis consists of the two long flexible finger-like fins, furnished with two
projectile spinous appendages as in vipers. (In Ckimcera the surfaces of the organs are also spinous, as in snakes). The two
spines found in cartilaginous fishes are homologous with the OS penis of mammals. In men this bony part has disappeared,
and we have only the soft spongy portions of the organ remaining; the quivering of the legs during connection seems the
echo, as it were, of the sensitiveness of the flexible posterior limbs of the skates 1!). As the thought of a comparison with the
Snakes cannot be said to have been exactly new at that time, so it is also the case with the homology with the os penis ; it is
already found in Ray (Willughby: De Hist. Pise. etc. 1686, p. 77). Gar man, 1. c. p. 199—200, subscribes the opinion of Agassiz.

1) Already I.e. 1839, p. 149; more decidedly in: Fragmentary Notes on the Generative Organs of some Cartilaginous
Fishes (Trans. Roy. Soc. Edinb. 1S61; vol.22, p. 500).

1 Introduction etc. p. 167. Gunther also supposes that the two appendices by being put together may form one
canal; he thinks it to be possible that the appendix-slit leads as well the secretion of the glandular bag as the sperm.

9) Besides to the palps of the Araneina, the thought will easily be led to the limbs that in the Crustacea, especially
1,11 Decapoda, have been developed for serving the copulation; not only Leydig and Steenstrup, as has been shown by
the above quotations, but also Mayer have thought of these; several other analogies indicated by Mayer are rather distant
a if they be not all so distant as those, attributed to M. by Petri: the thumb-swellings in the frogs, the spur of the
Ornithorhynchus — which analogies I have not at all been able to find mentioned in M.I.
According to Petri; I have not been able to find the essay in question.
") '■<'■ P- 330. The secondary function, which Petri (in accordance with Bloch) ascribes to them: to serve as an
organ of motion making the males more mobile than the females - especially in the Rays — may surely, to say the least
of it, be characterized as problematic.

ON THE APPENDICES t'.KNlTAl.KS iCLASPERS) IN THE SELACHIANS. 79

employment to be to act as a kind of dilators of the sexual organs of the female; he imagines
them to be introduced until the month of the oviduct, whereupon the M. dilatator dilates the ter-
minal part, so that the bore of the oviduct is enlarged, and the male also is enabled to draw the
female nearer to itself, in such a manner that he can with his urogenital papilla reach into the
cloaca of the female, and there discharge the sperm, which from there more easily may penetrate
into the mouths of the oviducts that have been dilated by the appendices.

None of the mentioned authors have been able to found their opinions on any observation
of the copulation 1 )- Only of late we have one, as it would seem, reliable observation, communicated
by Bolau 2 ), by which at all events it may be regarded as an established fact that the appendix is
reallv introduced into the genitals of the female. This observation applies to Scyllium stcllarc (catulus),
and is made in the aquarium of the zoological garden in Hamburgh. Before the copulation the male
for about a day kept near the female, and pursued her, but it was not observed in what manner he
seized her. During the copulation the female is encircled by the male, the latter, as it were, twisting
round her cross-wise; only one appendix, it would seem, is introduced at each copulation, and this
appendix, judging by the very incomplete sketch given by Bolau, (I.e. p. 322, fig. 2) must also after
the act be somewhat dilated. The copulation itself lasted in two observed cases 20 minutes. Bolau
follows Petri with regard to the interpretation of the part played by the appendix on this occasion;
but he adds that he is not able to decide, whether the appendix-slit^) plays a part by the conveying
of the semen.

This observation, as far as I know, stands hitherto quite alone; it seems to me to be of no
small interest, although it decides nothing with regard to the most important question, whether the
appendix really conveys the semen or not. As to this question we are still reduced to draw our in-
ferences from the structure of the organ. This structure seems to me to show with complete cer-
tainty that at all events the append ix -si it cannot be the duct of the semen; it is situated in
such a way, that it is impossible to understand how the sperm should get into it and follow it, as it,
as we have seen, is situated dorsally and laterally, sometimes (for inst. in the Skate] quite laterally;
the ventrals are not able to perform a movement of such a nature as to make the foremost opening

M Davy and Agassiz. however, — as also several of the earlier authors ifor inst. Rondelet) — have known the
following remark in Aristotle, which might be indicative of some observations really having been made in antiquity:
elm Si. rt;ES ui kwpaxkfac tfaa't xal ou\>£-(<'>pz'ja rwv asXayCuv ivia imioftzv wmrsp Tobq zoi/ag* (I.e. 5, chap. 5, § 14). If his last
communication (1S61, p. 500) where Davy rather decidedly declares in favour of construing the appendix as a < penis , he
mentions some circumstances supporting the notion of an • intromission », derived from Cenlrina , as for inst. that the cloaca
of the female is large enough to receive the appendix, that it appeared ..slightly lacerated at its superior commissure.) , and
that the mouths of the uteri protruded, and were red and blood-filled. Garni an (On the Skates (Rajce) of the Eastern Coast
of the United States. Proc. Boston Soc. Nat. Hist. Vol. XVII, 1874, p. 171), who, as mentioned, subscribes the opinion of
Agassiz, to whom he attributes the credit of the discovery of the functions of the claspers > , has observed 1 a fact that adds
a little emphasis to his I A. 'si discoverv viz: that in virginal Sharks the hindmost end of the oviduct is closed as by a kind of
hymen icomp. also Semper: Das Urogenitalsyst. der Plagiost. Arb. Zool.-Zoot. Inst. Wurzb. vol.2, 1875, p. 279), or provided
with a very small pore; this pore is round in the species of which the male has tapering claspers >, and forms a short, horizontal
slit in those where the claspers are flat with rounded ends; in the species where the appendix has sharp edges and hooks, the
hindmost part of the oviduct and the cloaca is very thick and leathery. In virginal Mustelus the oviducts were further-
more found stretching along the dorsal side of the cloaca to a point at the middle of the anus; in grown, impregnated
specimens thev are open, as if an inch or more had been cut off of the end, and the rectum opens in the cloaca between their
openings and the outer one.

-1 Cber die Paarung und Fortpflanzung der Scyllium-hxteu. Zeitschr. f. wiss. Zool. vol.35. 1881, p. 321.

3) He wrongly places the appendix-slit on the inner side of the organ, and its partly closed state in Scyllium seems
unknown to him.

8o ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIAN'S.

of the slit approach the cloaca of the animal itself (as supposed by A gas si z [and Garman]); neither
can a turning round the longitudinal axis be effected (least of all a turning of 180 3 , as would be re-
quired in the Skate), and thus any thought of a putting together of the slits of the two sides to form
a tube (Agassiz, Gunther) has to be dismissed (quite apart from the fact that in some forms -
Scyllium, Prist ittrits -- the appendix-slit is closed for a long way by coalescing). A putting together
of the medial sides of the two appendages ma)- however easily be effected by the Muse, adductores,
but by this no convenient way for the sperm would be formed; and the observation of Bolau
shows moreover that in Scyllium only one appendix is used at a time; for the present it may, how-
ever, be disputed, whether this is a universal law in all cases and in all other Selachians. Thus it
seems that the tubular, or rather semi-tubular form of the appendix cannot directly have anything to
do with the transferring of the semen; the most immediate purpose of this form evidently is the
transportation of the gland-secretion.

On the other hand the structure of the appendix shows with still greater certainty — quite apart
from the observation by Bolau -- that the appendix cannot be used for externally clasping the
female. For a great part, I think, it is the hooks, claws, or thorns, so often projecting through the skin
of the terminal part that have caused or supported this supposition. But an attentive observation of the
position and way of moving of these firm parts, as also of the whole constitution of the terminal part,
might, as it seems to me, rather easily have persuaded the many adherents of the theory of these organs
as -claspers , or «Klammerorgane», that they are only ill adapted for such a purpose. The skin of the
whole terminal part is, as we have seen, often quite naked and soft (the point itself is always so), and
the appendix would therefore -- as has been correctly pointed out by Agassiz -- be badly off with
regard to the rough surfaces, with which in most cases it would have to do, and against which it
would only be slightly protected by the secretion (Bloch; this secretion would rather be a hindrance
for the clasping, as is also remarked by Davy). In the /to/i?-species the hard skeletal parts whose
business would be to hold fast the female, only appear within the dilated terminal part, and are
wrapped by a specially vulnerable skin, very much like a mucous membrane; consequently, if these
parts were to hook on — for which their special shape is in no way adapted — for inst. to the thorny
tail of the female Ray (Cuvier & Valenciennes, Dumeril), their most immediate surroundings
would he much exposed to injury; and if we choose to regard such appendages as those in Acanthias,
Sommosus, or above all Spinax, which, by the hooks, thorns, or claws projecting freely through the
outer skin, may for a superficial examination convey the impression of being plain prehensile
organs (the dilated terminal part of Sfiinax reminds not a little of a bird's foot!), then any closer
examining will show that they cannot be such: the position of these claws is always so, that they
cannot catch an object, or clutch it. Besides their movement inward, against each other, when the
terminal part is closed, always takes place with small force, by elastic reaction of the connecting soft
parts, only to a small degree (and not in all cases) somewhat assisted by muscular action. The erec-
tion of these parts on the contrary, when the terminal part is opened by means of the always power-
ful At. dilatator, can take place with great force, and they may with force be kept spread out. I
think therefore that there can be no doubt, but that Davy has had an eye for the correct fact (al-
though the Rays especially examined by him, do not present the fact so clearly by far, as do Acanthias

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

or Spinax), when he supposes the appendices to be organs for intromission and retention like the
Penis of the Dog ; only in a hollow these spurs, thorns etc., can be of importance as
retentive organs; it is quite evident that they are barbs that are kept stiff, as long as the dila-
tion of the terminal part lasts. Viewed in this way the dermal teeth on the terminal part in Scyllium,
Pristiurus (and Chimcera) will also get importance, they being placed with their points towards the
base of the fin and raised by the dilation; they will also — although to a less degree — act as barbs.
When the dilation ceases, all these barbs - large and small - - are laid, and thus they present as
small resistance as possible by the extraction from, as well as by the introduction into a hollow. That
the object is that they may be introduced and extracted without resistance, is very finely shown in
some instances; this, above all, applies to the hook- (Td) in Acanthias; in the position of rest it fits
so elegantly into the spoonlike ventral terminal piece (Tv) as to remind of a surgical instrument 1 ).
All the appendices are moreover adapted for being thickly smeared with the viscid secretion of the
glandular bag, and accordingly being made smooth, by which an introduction into a relatively narrow
hollow ma}- be highly facilitated.

I think then that the structure of the appendix shows quite indisputably: i) that this
organ is intended for being introduced into a hollow, and 2) that it is able to fix itself in this hollow
by the dilation of the terminal part. In this way — but only in this way -- the appendix becomes
an organ of retention during copulation. It would a priori be the only reasonable supposition, that
the hollow of which the question here can be, must be the genitals of the female; by the observation
of Bolau this supposition has been made a certainty, and this gives to his observation its special
importance. My opinion then is, that at all events it may be put down as certain that the
ventral appendages during copulation serve as retentive organs in the genitals of
the female 2 ). But this can scarcely be their only function. My opinion is that they must have
several functions, among others to awaken the sensuality, and furthermore to open (or at all events
to widen) the mouths of the oviducts in virginal females, and thus secure impregnation and facilitate
the parturition ; and though I cannot imagine that the appendix-slit should form a duct for the sperm,
I still think it probable that the appendages in some way or other subserve the conveying of the
semen, so that it is not conveyed by means of the urogenital papilla of the male alone. And I also
suppose that the secretion of the glandular bag subserves this object. As we have seen, the secretion
is in all appendices not only evacuated through the hind end of the organ, in the terminal part, but
also in all instances through the opening at the base of the organ, and thus not only the genitals of
the female and the appendix itself, but most likely the whole immediate surrounding of the cloaca in
both the copulating animals will be lubricated by the secretion. The consequence of this will be
that the sperm will easily be mixed with the secretion, and it may readily be supposed that this
mixing may have a stimulating influence on the spermatozoids, or act as gathering and conveying

M Gegenbaur, who does not at all mention the function of the appendix, says of these parts in Acanthias (I.e.
p. 4521: -Das Verhalten beider Stiieke ahnelt den verdeclcten Haken, wie sie als chirurgische Instrumente gebraucht werden .

2 ) The old, before quoted observation in Aristotle gains by this view very much in trustworthiness: cThere are
those who assert that they have observed that some of the Selachians hang together behind like the Dogs > ; and it lies near
to suppose that it is this kind of < hanging together-, that is suggested by Pennant (Brit. Zoology. New. Ed. 1812, Vol. Ill,
p. 112) of the Skate: ....several of the males pursuing one female; and adhere so fast during coition, that the fishermen
frequently draw up both together, though only one has taken the bait .

The Ingolf-Expedition. II. 2. II

82

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

the semen, preventing it from flowing off in the water. Then the part played by the secretion, would
not be restricted to facilitating the introduction of the appendix — which part I regard as quite in-
contestable — , and to protect the different parts partaking in the copulation (eventually also the outer
skin) against a severe friction; but the secretion would also be of direct importance for the impreg-
nation by yielding a means, as it were, of keeping together the semen and leading it along the
appendix into the oviduct.

It must be possible to some degree to test this supposition by examining the way in which
the spermatozoids act in relation to the fresh secretion; but unfortunately I have had no oppor-
tunity for that 1 ). For the present I must leave the value of this and my other suppositions to the
testing of others, and own that I have only been able to advance the understanding of the func-
tions of the ventral appendages very little; most of the questions raised by the different, rather com-
plicated structures, especially in the terminal part, must still be left quite unanswered, as also such
facts as the large extent of the glandular bag in most Sharks must still appear mysterious 2 ). With
regard to some of these questions it may be dubious, whether they ever will be solved; but with
regard to others, especially the question of the appendages as means of the conveying of the semen,
it would seem that they might be solved by observations. It is to be hoped that the future will
bring such observations.

Addenda.

I have been unwilling in this translation to make any essential alterations of the original
Danish text. This latter was ready printed in August 1898. I regret to say that shortly after I
saw that I had quite overlooked a short, but rather essential contribution by A. Schneider to the
question of the function of these organs; it is only little more than half a page, and is printed in
Zool. Beitrage vol.1, 1885, p. 6i3). In this contribution he says of the glandular bag: < Dieser Sack
hat jedoch noch eine andere bisher ganz iibersehene Function. Er ist ein Receptaculum seminis, Ich
habe bei Sfiinax Acanthias Samen dariu gefunden. Die Begattung diirfte deshalb bei den Plagiostoiinn
in der Weise stattfinden, dass zuerst das Receptaculum seminis mit Samen gefiillt wird unci von da
aus mit Hiilfe des in den Uterus eingefuhrteu Pterygopodium die Immissio seminis stattfindet. Bei

M Hitherto only very little is known of the chemical relations of this secretion. Davy (I.e. 1S39, p. 145) says it is
neither acid nor alkaline, and that it has a very indistinctly acrid after taste. Moreau, on the contrary, declares it to be
acid (I.e. p. 258); this, however, can scarcely be correct, as in this case it would have a bad influence on the spermatozoids
with which it will scarcely avoid to come into contact.

2 ) For those, who are of opinion that Agassiz has solved the question of the function of the appendages correctly,
these bags, perhaps, will not appear quite so mysterious; Garman, for inst. says (Proc. Bost Soc. 1874, p. 173): «That the
cavity upon the ventrals, containing the muscular gland, fills so readilv with the sperm when the claspers are erected, and
that its contents are expelled, upon contraction of the muscles around it, with such certainty to their ends, when restored to
their normal position, are evidences that it acts as a forcing or squirting apparatus . I must, however, object against this
1 that I cannot see that the sperm upon the whole can he filled into the bag, still less, that it can be done easily; and
2\ that spermatozoids never have been found in the glandular bag, although its contents have several times been subjected
to microscopical examination, also with the object of seeking spermatozoids in them.

3) As it is reported in Biol. Centralbl. < vol. Ill, 1S83, 110.7, p. 224, this contribution to the Beitrage* must have
appeared two years before the completing of the said volume.

ON THE APPENDICES GENITALIAS (CLASPERS) IN THE SELACHIANS. 83

den Holocephali) Callorhynchus und Chimara besitzt das Mannchen vor dem Pterygopodium jederseits
einen sehr verwickelt gebauten Apparat Derselbe besteht aus einer Tasche, in welcher mehrere,
Knorpel enthaltende , mit Widerhaken versehene Stiicke hervorgestreckt werden kouuen. Ich fand
diese Tasche bei Callorkynckus mit Samen geftillt. Aueh bei dieser Gruppe der Elasmobrauchier
wird demnach der Samen vor der Begattung naeh aussen gebracht. Wie freilieh hier die Begattung
stattfinden wird, lasst sich vorlaufig nicbt angeben. The essential thing is that Schneider declares
to have found sperm in the bag in Acanthias and in the pouch of the pelvic appendages in Callo-
rhynchus\ certainly no proof is given, but we shall have to suppose that Schneider has really found
the spermatozoids. Whether these have been numerous, that is to say, whether the bags in question
really can be said to have been filled with the semen, of this we know nothing with certainty, and
we can -- in mv opinion -- not yet in any way put it down as an indubitable fact that the glandular
bag of the Plagiostomes is a reservoir that has to be filled with the semen and by the copulation to
eject it Nothing is said of the way, in which the filling of the bags in question should take place.

I have unfortunately not been able to get a paper by Ha swell (Notes on the claspers of
Heptanchus. Proc. Linn. Soc. N. South Wales, vol.9, p - 2 i P- 3 8l l-

During the time between the appearing of the present essay in Danish and this translation I
have received a paper bv H. C. Red eke (Onderzoekingen betreffende het Urogenitaalsystem der Se-
lachiers en Holocephalen. Acad. Proefschrift etc. Helder 1898) in which (p. 77) after a representation
of what till then was known regarding the appendages and their function, the author declares that
he has himself found numerous spermatozoa in the < mixipterygoid bags 1 ) in one single specimen
among many examined specimens of Mustelus vulgaris. He calls, however, attention to the fact that
the bag was not filled, which fact he explains by supposing, either that the animal during its agony
might have emptied the bag, or rather that these animals will copulate, as soon as the bag is filled.
An observation bv another observer, respecting a male Raja clavata that had ejected an abundance of
semen through the dilated appendices, can scarcely be regarded to be of any value, as there is no
proof to the effect that the ejected fluid in reality was semen and not the secretion from the gland.
Finally is quoted an observation by Professor M. Weber, which observation the author thinks may
be used to explain, in what manner the filling of the glandular bag might be brought about. I shall
give the proper words of the author, and else abstain from advancing my strong doubt of the fact:
«Deze (Prof. Weber) nam waar, hoe een groote Rog (Raja clavata) rondzwemmende in eeu der bassins,
plotseling eeu groote wolk, vermoedelijk sperma, loosde en vervolgens, misschieu reflectorisch, heftig
met ziju mixipterygien begon te zwaaien, die daarbij een pompende beweging schenen uit te voeren.
Het is niet onmogelijk, dat 00k in de natuur, al is de omweg een allerzouderlingste, het sperma eerst
in een groote hoeveelheid geloosd en gelijktijdig door de mixipterygien in den zak opgezogeu wordt.

1) The appellation of Mixipterygium, which has of late often been used in stead of the objectionable „ Pterygopodium
of Petri, is due to Gegenbaur (Das Flossenskelet der Crossopterygier etc. Morph. Jahrb. vol.22, 1895, p. 146, note')).

g 4 ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS.

EXPLANATION OF THE FIGURES.

A : Mus cuius adductor,
a/: The appendix-slit.
B: The basale metapterygii.
b: The appendix-stem.
b 1} b 2 , b iy b 4 : The stem-joints between the appendix-stem and the basale.
ft: The dorsal stem-piece.
D: Musculus dilatator,
d, r/j, d 2 , d % : Dorsal covering pieces.

da ly da: Terminal pieces belonging to the ventral side (in some i?«/#-speeies).
E: Mu sen lits extensor.

g: The end-style, the micalcified end of the appendix-stem.
//: Horny filaments.
O, O': Fin-mnscles arising from the body.
P: The pelvis.
R: Marginal ray.
;■: Rays.
Ra: Ray-muscles.

Rd: The dorsal marginal cartilage.

Rd ': Process from the dorsal marginal cartilage (in Raja-species).
Rd 2 : A special terminal piece, added to the dorsal marginal cartilage.
Rv: The ventral marginal cartilage.
JT: JMusculus compressor.

s: A ligamentous septum, serving for attaching part of the Muse, adductor.
Td, Td 2 : Dorsal terminal pieces.
Tv, Tv 2 , T 3 : Ventral terminal pieces.
v, v' : Ventral covering pieces.

ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 85

Plate I.
Fig. 1 — 9. Somniosus microcephalia.

Fig. 1: The skeleton of the right ventral, viewed from the dorsal side; considerably reduced.

2: The chief piece of the right appendage, viewed from the dorsal side; reduced. / the lateral
surface; x articular surface for attaching the piece /?.

— 3: The same skeletal part, from the ventral side.

— 4: The dorsal terminal piece, Td, from the dorsal side.
5: The same piece, from the ventral side.

— 6: The ventral terminal piece, Tv, from the dorsal side.

— 7: The same piece from the ventral side.

8: The * thorn or spur*, T 3 , from the dorsal side.

— 9: The same, from the ventral side.

Fig. 10 — 11. Acanthias vulgaris.

Fig. 10: The skeleton of the right appendage, from the dorsal side; natural size.

— 11: The same skeletal part, from the ventral side.

Fig. 12 — 13. Spinax niger.

Fig. 12: The skeleton of the right appendage, from the dorsal side; a little enlarged.

— 13: The same, from the ventral side.

Fig. 14 — 15. Chimcera monstrosa.

Fig. 14: The skeleton of the right ventral, from the dorsal side; natural size, x process on the piece
b x \ 6*, d**, d*** the medial, dorsal, and lateral branches af the appendix-stem.

— 15: The same skeletal parts, from the ventral side.

Plate II.

All the figures represent the skeleton of the appendage of the right ventral fin (or parts of it).

Fig. 16 — 17. Scyllium canicula.

Fig. 16: The skeleton of the appendage, from the dorsal side; natural size.

— 17: The same, from the ventral side.

Fig. 18 — 19. Scyllium stellare.

Fig. 18: The appendage, from the dorsal side; natural size.

— 19: The same, from the ventral side.

86

ON THE APPENDICES GENITALEB (CLASPERS) IN THE SELACHIANS.

Fig. 20 — 21. Pristiurus melanostomus.

Fig. 20: The appendage, from the dorsal side; natural size.

— 21: The same, from the ventral side.

Fig. 22 — 23. Lamna cornubica.

Fig. 22: The appendage, from the dorsal side; much reduced.

— 23: The same, from the ventral side.

Fig. 24 — 27. Rhina squatina.

Fig. 24: The appendage, from the ventral side; reduced.

— 25: The distal end of the same, from the dorsal side; * indicates the place where the terminal

piece T z ends, hidden in the ventral marginal cartilage Rv.

— 26: The same part, from the ventral side; the covering piece v removed.

— 27: The terminal pieces Tv and T z figured separately.

Plate III.

All the figures represent the skeleton of the appendage of the right ventral fin (or parts of this skeleton).

Fig. 28 — 31. Torpedo marmorata.

The distal end of the appendix-skeleton, from the dorsal side; about natural size.

The same; the covering piece r> removed.

The same, from the ventral side.

The same, from the ventral side; the covering piece v removed.

Fig. 32 — 34: Narcine sp.

The appendage, from the dorsal side; somewhat enlarged; the covering piece v removed.

The same, from the ventral side.

The covering pieces v and 7 ,f , from the dorsal side.

Fig. 35 — 37. Rhinobatus columnce.

The appendage etc., from the dorsal side; about natural size; the covering piece s removed.

The same, from the ventral side.

The terminal point of the appendage, with the covering piece v, from the ventral side.

Fig. 38 — 40. Trygon violacea.

The appendage etc., from the dorsal side; about natural size; the covering pieces v and v\

removed.
: The terminal part of the same, from the ventral side, with the covering pieces v and v'.
: The appendage from the ventral side; the covering pieces removed.

Fig. 41 — 44. Raja circularis.

The terminal part of the appendix-skeleton, from the dorsal side; natural size.

The appendage from the dorsal side; the covering piece d^ and the terminal piece T 3 removed.

The terminal part of the same, from the ventral side.

The appendage, from the ventral side; the covering piece and the terminal piece T 3 removed.

Fig.

28

—

29

—

30

3 1

Fig.

32

—

33

34

Fig

35

—

36

—

37

Fig- 38:

- 39
40

Fig. 41
- 42

' 43
■ 44

ON THE APPENDICES CENITAEES (CLASPERS) IN THE SHI. ACI I IANS.

87

Plate IV.

All the figures represent the skeleton of the appendage of the left ventral fin (or parts of this

skeleton).

Fig. 45 — 48. Raja batis.

Fig. 45: The terminal part of the skeleton of the appendage, from the dorsal side; considerably re-
duced; the covering piece d and the terminal piece 7" 3 removed; x a calcified part of the
end-style g.
46: The same, from the ventral side; all the pieces present.

- 47: The same, from the ventral side; the covering piece and the terminal piece T 3 removed.

- 48: The dorsal covering piece, d, seen from the dorsal side.

Fig. 49

50

5 1

Fig- 53 :

54
55
56

3/ •

Fig. 49 — 52. Raja clauata.

The appendage with all its pieces, viewed from the dorsal side; considerably reduced.

The same, from the dorsal side; the covering piece d removed.

The same, from the ventral side, with all the pieces present.

The same, from the ventral side; the covering piece (/ and the terminal piece T % removed.

Fig- 53—57- R<y' a radiata.

The skeleton of the appendage with all its parts, from the dorsal side; reduced; x thickened
and calcified part of the end-style g.

The same, from the dorsal side; the covering pieces d z — d 3 removed.
The same, from the ventral side; all parts present.

Part of the dorsal wall of the appendix-slit, viewed from the ventral side; the ventral mar-
ginal cartilage and all the terminal pieces of the ventral side, as well as the covering pieces
removed. Rd' is here an independent piece.

The terminal part of the ventral marginal cartilage with the terminal pieces Tv and Tv 2 ,
separated from the other skeletal parts, and viewed from the dorsal side (i. e. part of the
internal side of the ventral wall of the appendix-slit).

Fig.

08:

59:
60:

61:

62:

Plate V.

All the figures represent the right ventral fin.
Fig. 58 — 62. Somniosus microcephalus.

Ventral fin, viewed from the ventral side, of a young specimen, 2 m 50 cm long; considerably

reduced.

Part of the same ventral fin, viewed from the dorsal side and a little turned.

Part of the ventral of a large specimen, seen from the ventral side; considerably reduced.

The terminal parts, with the exception of part of the spur 7" 3 , covered by aponeurosis.

The same, from the dorsal side; part of the dorsal ray-muscles, Ra , removed, as well as

part of the muscular portion O arising from the body; a aponeurosis of the Muse, extensor E.

Part of the same, showing the muscles of the appendix, after removing the Muse, extensor E,

the muscular portions O and O' (corap. fig. 59), as also part of the glandular bag (comp. fig. 61).

88 ON THE APPENDICES GENITALES (CLASPERSl IN THE SELACHIANS.

Fig. 63 — 64. Acanthias vulgaris J.

Fig. 63: Ventral fin from the ventral side; natural size.

■ 64: The same from the dorsal side; most of the muscles arising from the body removed.

Plate VI.

The figures, except fig. 67 — 68, represent the right ventral fin.

Fig. 65 — 66. Scylliam stellare.

Fig. 65: The ventral fin from the ventral side; somewhat reduced; the greater part of the glandular
bag S removed; a Z) a 2 special muscles of the appendix; /"the winglike process.

— 66: The same, from the dorsal side; af the basal opening of the appendix-slit.

Fig. 67 — 68. Raja clavata.

Fig. 67: The left ventral fin, from the dorsal side; considerably reduced; the terminal parts covered
by the aponeurosis.

— 68: The same, from the ventral side.

Fig. 69 — 71. Chimcvra monstrosa.

Fig. 69: The right ventral fin, from the ventral side; a little reduced; the skin on the branches

of the terminal part not removed; b* the medial terminal branch, b** the dorsal one, b***

the lateral one; p the serrated plate covered with its skin.
70: The same, from the dorsal side; m the muscle of the serrated plate ; x process on the

piece b Y .
71: Part of the same, from the ventral side; the ventral portion of the Muse, adductor, A in

fig. 70, removed.

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