174 



HOLOCEPHALI 



other hand, differs considerably from that of the Selachian, in that 

 the two halves are not fused and the iliac process is Avell developed. 

 In the male an anterior clasper, armed with denticles and lodged in 



FIG. 139. 



Chiinaera tnongtrota, L. A, ventral view of the right pelvic fin of a male. B, ventral 

 view of the left half of the pelvic girdle and pelvic fin of a male (after Davidotf). C, diagram 

 showing the opening of rectum and urinogenital sinus in the female, a.c, anterior clasper 

 armed with denticles ; an, anus ; a.p, abdominal pore ; b, basipterygium ; d, posterior clasper ; 

 il, iliac process ; k.d, kidney duct ; od, oviduct ; p, pelvic cartilage ; p.f, pelvic fin ; pt, pocket 

 into which the anterior clasper can be withdrawn ; r, radial ; rt, rectum ; tr, tritid extremity 

 of clasper ; tr.c, its cartilage cut short ; ug, urinogenital papilla ; ttg.h, its opening ; itg.s, 

 urinogenital sinus. 



a pouch, is borne by a cartilage attached to the girdle, at all events 

 in living Holocephali and in Squaloraja (Figs. 139, 141). This 

 anterior clasper, unique amongst fish, is doubtless formed by the 



