202 FOREIGN JURASSIC POLYCYPHUS. 



Polycyphus distinctuS; Agassiz. Syn. Echinus distinctus, Agassiz. Cat. raisonne, An. 



Sc. Nat., tome vi, 3 me serie, p. 366. 



" A very large depressed species ; inter-ambulacra with from ten to twelve rows of 

 tubercles ; ambulacra with four rows of tubercles, the two internal rows much more 

 irregular than the external. 



" Formation. — Corallien d'Angoulin pres la Rochelle. 

 " Collection. — M. d'Orbigny : rare." Desor. 





