3° 



ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 



Td 



quite soft. Lilljeborg 1 ) only says: The copulatory organs of the male are small and pointed, and 

 ■ h only a little behind the ends of the ventrals; the}' 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 cm — 38,5 cm the following measures are found 2 ). 



Length of appendix (from the fore edge of the cloaca) . . abt. 2,5 cm — 35 c,n 



- the part, free of the fin 



- the terminal part 



- the appendix-slit 



Breadth of the appendix 



The skeleton. Between the basale and the appendix are found two small pieces (6 Z and d 2 ), 

 each bearing one of the two hindmost rays (accordingly b z + b, in Sfiinax = b t in Acanthias)\ never- 

 theless these rays may be found coalesced, and are, as usually, directed straight backward, parallel to 

 the appendix. The piece /J is relatively somewhat longer than in Acanthias, but of a similar form. 



The axial part of the chief piece of the appendix is somewhat more clumsy than in Acanthias, 

 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. 



Fij 



Fig. 5. Spinax nigcr. The appendage of the right side 

 with part of the fin-membrane, seen from the dorsal side, 

 somewhat enlarged. The terminal part is dilated. / the 

 folded, free end of the fin-membrane; at the fin has 

 cut from the body. aj\ the dilated part of the 

 appendix-slit. 



Fig. 6. The dilated terminal part, seen from behind, a 

 tlie soft terminal flap, af the spot where the appendix- 

 slit passes into the dilated, terminal part of the furrow. 



T -7C111 



0i 6cm — o^Sc 



■i Syenites och Norses Fiskar, vol.;,. 1N91, p. 677. 



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



