298 COMPARATIVE ANATOMY CHAP. 



Fam. 1. Linckiidse : Cliaetaster, Ophidiastcr, Linckia, Metrodira, etc. Fam. 2. 



Km. 'J4L'. Hymenaster caelatus (afti-r Sladen), witli anus brut back. 



Zoroasteridse : Zoroaster, Cncmidasfcr (Fig. 241). Fam. 3. Stichasteridae : Sti- 

 chastcr, etc. Fam. 4. Solasteridae : S'0/W<v. <'i-t>*s(tstcr, Cb/vM/VN/.T, etc. Fam. 5. 



1 



Fiu. i'43. Hymenaster nobilis (after Sladen), from the oral side, I natural size. 



Pterasteridse, with brood cavity on the apical side of the disc : Pteraster, Retastcr, 

 Hymenaster (Figs. 242 and 243), Myxastcr, Bcnthastcr, Pythoiiastcr, etc. Fam. 6. 



