ASTEROIDEA. 23 



Family 3. CORETHRASTERID^E* 



Korethrasteridae, Dan. <§• Kor. Norsk. Nordh. Exp., Aster. (1884) 

 p. 99. 



Allied to the Asterinidse, but distinguished by the complete 

 absence of interbrachial spaces, and by the possession of a con- 

 tinuous calcareous plating, and the formation of the paxillae. 



One genus : C or ethr aster. 



» v 



Family 4. PTERASTERID^E. 



Pterasteridae, Perrier, Arch. Zool. iv. (1875) p. 302 ; Viyuier, op. cit. 



vii. (1878) p. 224; Perrier, Nouv. Arch. Mus. vi. (1884) p. 216; 



Sladen, Chall. Pep. Ast. (1889) p. xxxvii. 

 Velatas, Perrier, Miss. Cap Horn, vi. (1891) p. k 72. 



Cryptozonate Asteroidea in which the dorsal ossicles carry a spine 

 crowned by long diverging spines which support a more or less well- 

 developed membrane ; this forms a marsupial recess for the young. 

 No actinal intermediate plates, interbrachial septa, or pedicellarias. 



Two genera : Pteraster and Hymenaster. 



Family 5. ECHINASTERID^l. 



Echinasteridae, Verrill (no diagnosis), Trans. Conn. Acad. i. (1867[71]) 

 p. 343 ; Perrier, Arch. Zool. iv. (1875) p. 299 ; Viyuier, op. cit. vii. 

 (1878) p. 121 ; Perrier, Nouv. Arch. Mus. vi. (1884) p. 206 ; Sladen, 

 Chall. Rep. Ast. (1889) pp. xxxviii & 535. 



One subfamily. 



Subfamily ECHINASTEEIN.&. 



Eehinasterinae, Viyuier, Arch. Zool. exper. vii. (1878) p. 123 ; Sladen, 

 Chall. Rep. Ast. (1889) p. xxxviii. 



Echinasterida? with rather small disk and five or six rays ; spines 

 small, simple, solitary or grouped. No pedicellarise. 

 One genus : Henricia. 



Family 6. ASTERIIDtE. 



Asteriadae, Gray, Aim. §• May. vi. (1840) p. 178 ; Norman, Ann. 



Sr May. xv. (1865) p. 125 ; Perrier, Arch. Zool. iv. (1875) p. 299 ; 



Viyuier (s. em.), op. cit. vii. (1878) p. 93; Perrier, Nouv. Arch. 



Mus. vi. (1884) p. 199. 

 Urasteriae, Forbes, Brit. Star/. (1840) p. 77. 

 Erste Faniuie, M. Tr. Syst. Ast. (1842) p. 11. 



* The only specimen available to me is the type of Wyville Thomson, which 

 has been investigated by Mr. Sladen. 



