596 



NORTH AMERICAN INDEX FOSSILS. 



38. C. florealis (Morton). (Fig. 1928, c?-^.) Cretacic. 

 Marginal outline somewhat five-angled, angular posteriorly. 



Apex slightly in front of center. Interambulacra wide, covered 

 with small perforated tubercles ; peristome pentagonal, with the 

 ambulacral areas near it broadened and conspicuous; periproct in 

 a short, narrow furrow. 



Ripleyan of New Jersey (?) and Delaware. 



39. C. aequoreus Morton. (Figs. 1929, 1930.) Cretacic. 

 Differs from preceding in its more depressed and elongated 



form. 



Ripleyan of New Jersey and Alabama. 



Fig. 1929. Cassidulus cpquoreus. a, dorsal view ; b, ventral view ; Cy lateral 

 t view ; (/, posterior view. (After W. B. Clark.) 



Fig. 1930. Cassidulus aquoreus. a, diagram showing arrangement of plates into 

 a floscelle around the peristome ; b, apical disc, much enlarged ; <r, several plates of 

 petaloid region of anterior ambulacrum, much enlarged ; d, anterior ambulacrum en- 

 larged ; <?, several plates of same, of oral region, much enlarged. (After W. B. Clark.) 



XXVI. EcHiNOCORYS Breyn. (Ananchytes Mercati.) 

 Test large, oval in marginal outline, high. Upper surface 

 rounded or keeled. Lower surface flat. Ambulacra with but two 



