VIII 



ECHINODERMATA SYSTEMATIC REVIEW 



29' 



Pentaceros, Amphiaster, Culcita, Asterodiscus, etc. 

 nasteria, Tylaster, Astevopsis, 

 Marginaster, etc. Fam. 8. As- 

 terinidae : Gaiieria, Asterina, 

 r<tl,nipes, etc. 



Order 2. Cryptozonia. 



Asteroidea, in which the mar- 

 ginal plates are indistinct and 

 more or less rudimentary in the 

 adult. The supramarginal plates 

 are often separated from the in- 

 framarginal by intermediate plates. The 

 papulae are not limited to the apical sur- 

 face, but often occur also between the 

 marginal plates and on the oral (lower) 



Fam. 7. Gymnasteriidae 



FIG. 240. Anthenea tuberculosa, Gray? 

 juv. (after Sladen). 1, Supramarginal plates ; 

 2, pedicellarise ; 3, madreporite ; 4, anus. 



FIG. 241. Cnemidaster Wyvillii (after Sladen). ilc, Dorsocentral ; r, radials ; be, basals ; 

 sm, suprainarginals ; d, dorsals ; t, terminals. 



surface of the body. Ambulacral plates narrow, closely crowded. Tube-feet often 

 in four rows. In the oral skeleton the ambulacral or interambulacral plates are 

 prominent. Pedicellarire sessile or pedunculate. 



