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, bnt none of them protrudes with any part through the skin. 



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



Scyllium stellare (L.) 



(PI. II, fig. '8-19; pi. VI, fig. 65-66.) 



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 cm the 

 coalesced part has a length of i6 mm ); the 

 small cut in the posterior edge in Sc. 

 cannula has here become a large slit 

 (in the specimen mentioned above about 

 26 mm ); the dermal teeth also spread to a 

 greater extent on the ventral side of this 

 part of the fin. As furthermore no lateral 

 fold of the skin is found on the ventral 

 side covering the base of the appendices, 

 and corresponding to the one mentioned in 

 Sc. amicula, no bell is formed here. 



The appendix reaches just outside 

 the posterior fin edge; it is far more big 

 and clumsy than in Sc. canicula, but still 

 the details remind of the latter, thev are 

 only coarser and more conspicuous. 

 In a specimen of a total length of go '" the following measures were found: 



Pig. 8. 



Fig. 7. Scyllium slellare. The appendage of the right side seen 

 from the ventral side; about the natural size, ab abdominal pore. 

 F fin-membrane, f winglike process. 



Fig. 8. The same appendage seen from the dorsal side; the coa- 

 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 

 brought into the appendix-canal. 



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



- free part .,6'"'" 



terminal part 34 m '" 



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 



'I When Lilljeborg 1. c. p. 655 tells that the ventrals in Sc. stellare are not coalesced, he is not quite right. M tiller 

 & Henle 1. c. p. 10 state the fact correctly. 



