XVll 



ZYGOPHIURA5 



495 



Order II. Zygophiurae. 



This group includes all the common and better-known British 



Fig. 217. — Atoral view of Ophioglypha (OpMura) hullata. x 3. (Prom Wyville Thomson.) 



forms. They are divided into five families, all of vrhich are 

 represented in British waters. 



Fam. 1. Ophiolepididae.^ — Arm inserted in a definite cleft 



^ Hamann, Bronn's Thier-Reiah, Bd. ii. Abt. 3, Ophiuroidea, 1900, p. 910 f., 

 discriminates a family Ophiodermatidae, but gives no character by whicli it can 

 le distinguished from Ophiolepididae. 



