ON THE APPENDICES GENITALES (CLASPERSj IN THE SELACHIANS. 



Between the basale and the appendix-stem is found one piece b t bearing the two hindmost 

 The piece ft is rather large, flattened, with an edge turned towards the dorsal side. 



The appendix-stem is as long as B -)- b x \ 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 ,r, 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~ 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 mannlichen 

 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.|. 



(PI. II, fig. 16, 17). 



The copulatory organs are mentioned by several authors, generally, however, without auv 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.stellare 

 (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. By 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""') is straight, posteriorly some- 



■) See for inst. Muller & Henle, I.e. p. 7, 10. Krayer, I.e. p. 824. Dumeril, I.e. p. 316, 317. Lilljeborg, 

 I.e. p. 650. Petri, I.e. p. 303, and fig. 6. 



2 ) The words of Lilljeborg 1. e. p. 650: The male has small copulatory organs, not reaching to the hindmost points 

 of the ventrals, and scarcely of half of the above given length of these fins do not apply to the developed state. Neither 

 can the figure 6 of Petri represent the developed appendages, and it is upon the whole bad; the appendages are in this 

 cies never so clumsy; the description at p. 303 is only ill adapted to Sc. canicula, and not very well to Sc. catulus. 



