50 BRITISH PALAEOZOIC ASTEROZOA. 



Ophiuroid-like forms with ancestral primitive features somewhat disguised by 

 various forms of specialisation more or less peculiar to the period in winch they 

 lived. That this is the correct interpretation can, perhaps, be seen even more 

 clearly if we put out in full the list of Palaeozoic " Ophiuroidea," " Asteroidea," 

 and " Auluroidea " as given in Schondorf's latest list (68, pp. 249 — 252). 

 Schondorf's classification is as follows : 



Class OPHIUROIDEA. 



Onychastcr flexills. Meek ;iud Wurthen, Eiidadui Jnhnsoiii, Woodward. 



Class ASTEEOIDEA. 



Phanekozonia. 



Family Palajasteridje. 



Palxaster nia<jarensls. Hall, ? P. luatutiinis, Hall, P. raradaci, 



Gregory, Spaniaster latiscutatus, Saiidberger. 

 Family Xenasteridaj. 



Xenaster, Aijalmader, Bhenaster, Trimerasier, Eij'elaster, Mio- 



master. 



Crtptozonia. 



Family Palasterinidse. 



Palasterina, Lindstrom aster, Sdmdiediu, Asterias acuminata, 

 Simouow., Palivaster Diontanxs, Sturowsky. 

 Family Calliasteridae. 



Calliaster, Trautscliold. 

 Class AULUROIDEA. 



Ophiurasteriie, with opposite ai)ihiihicrnlia. 

 Phanekozonia. 



? Ophiuritta, Stiirtz. 

 Cryptozonia. 



Lapivortliura, Gregory, tSumpterura, Bather, ? Studzura, Gregory, 

 ? Gregoriura, Chapman, Studzaster, Etheridge, Fn roaster, Stiirtz, 

 Eospondylus, Gregory, Eoluidia, Stiirtz, Miospondyhis, Gregory, 

 Cheiropteraster, Stiirt z. 

 EncrinastericV, ivith alternating amhidacralia. 

 Phanekozonia. 



Aspidosoma , Goldfnss. 

 Cryptozonia. 



Protaster scdgwicki, Forbes, P. biforis, Gregory. 



It is seen that only two species are placed by iSchondorf among the 0})hiuroidea, 

 namely, Eucladia joli/nsoiii and Oni/chastei' Jiexilit!. 



Eiichidia jokiisoni, according to Sollas and Sollas (71, p. 222) should be 

 removed from the Ophiuroidea and placed in a separate class, the Ophiocistia, 

 possibly allied to the Ophiuroidea. My own observations suggest that Encladia 

 can have no near affinity with the Asterozoa. 



Oiii/chaster jiexilis has been shown by Miss Sollas (72) to have the enclosed 

 canal of the Auluroidea. 



