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- 



