VIII 



EGHINODERMA T A SYSTEM A TIC HE VIE W 



297 



Pcntaceros, Amphiaster, Gulcita, Asterodiscus, etc. 

 nastcria, Tylaster, Astcropsis, 

 Maryinaster, etc. Fam. 8. As- 

 teriniclse : Gancria, Asterina, 

 Pahnipes, etc. 



Order 2, Cryptozonia. 



Asteroidea, in wliirh the mar- ..---; 

 ginal plates are indistinct and H$| 

 more or less rudimentary in the 

 adult. The supramarginal plates x?; 



are often separated from the in- 

 framarginal by intermediate plates. The 

 papulpe are not limited to the apical sur- 

 face, but often occur also between the 

 marginal plates and on the oi-al (lower) 



Fam. 7. Gymnasteriida : Gym- 



FIG. 240. Anthenea tuberculosa, Gray? 

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

 2, pedicellaria; ; 3, inadreporite ; 4, anus. 



FIG. 241. Cnemidaster Wyvillii (after Sladen). dc, Dorsocentral ; r, radials ; bn, basals ; 

 sm, supramarginals ; 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. Pedicellariiie sessile or pedunculate. 



