170 ANELASMA SQUALICOLA. 



Capitulum without valves ; aperture large ; peduncle 

 fimbriated, sub-globular, imbedded. 



Cirri without spines; outer maxillae and palpi rudi- 

 mentary, spineless ; mandibles minute, with several small 

 teeth irregularly placed; maxillae minute, with very mi- 

 nute irregularly scattered spines. No caudal appendages. 



I owe to the great kindness of Professor Steenstrup, an 

 examination of this very curious cirripede, well described 

 and figured by Loven, who considered it an Alepas. It 

 lives parasitic, with its peduncle imbedded in the skin of 

 sharks, in the North Sea. According to the principles of 

 classification which I have followed, this cirripede cannot 

 possibly remain in Alepas, and must form a new genus ; 

 for some time, indeed, I thought that a new family or 

 sub-family ought to have been instituted for its reception ; 

 but when I considered that its highly peculiar characters 

 are all negative, as the non-articular, non-spinose structure 

 of the cirri, and that no new or greatly modified functional 

 organ is present, I concluded that it might properly 

 remain amongst the Lepadidae. We shall, moreover, 

 hereafter see that the male of Ibla, which, of course, must 

 remain in the same family with the female, is, in some 

 analogous respects, even more abnormal than Anelasma. 



1. Anelasma squalicola. PI. IV, figs. 1 — 7. 



Alepas squalicola. Love?/, ut supra. 

 North Sea. Parasitic on Squalus. 



Capitulum, destitute of valves ; oval, much flattened ; 

 the double membrane composing it, thin, highly flexible, 

 coloured externally and internally, by the underlying 

 corium, of a blackish purple ; aperture, extremely large, 

 extending from the upper end of the capitulum, to close 

 above the peduncle, gaping, and not protecting (in the 

 dead condition) the cirri and mouth. 



