PLATE XXXV. 



Cassidull's roRRECTUS Clark (page 72). 



Fig. la. An ambulacial area, enlarged. 



11). Lower portion of petaloidal region, highly magnified. 

 Ic. Central portion of same, highly magnified. 

 Id. Three interambulacral plates, much enlarged. 



Cassidulus Sxantoni Clark (page 73). 



Fig. 2a. Upper surface of the test. 

 2?>. Lower surface of the test. 

 2c. Lateral view of the same. 

 2d. Posterior view of the same. 

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