ECHINODERMATA. 305 



central, slightly depressed. Oral opening transversely subellip- 

 tical, situated near the anterior margin. Anal opening small, 

 subelliptical, situated but a short distance above the posterior 

 margin. 



The dimensions of a complete individual are : length, 53 mm. ; 

 width, 50 mm. ; height, 28 mm. 



Remarks. — This species is the only known American repre- 

 sentative of this genus, and it is not closely allied to any of the 

 European species. 



Formation and locality.- — Vincentown limesand. Timber Creek 

 (Clark). 



Geographic distribution. — New Jersey. 



20 PAIv 



