FOREIGN OOLITIC HEMICIDARIS. 105 



marginal granules above. Inter-ambulacral areas with seven tubercles in each row ; 

 areolas confluent. Apical disc prominent, the anterior pair of genital plates the largest. 

 Mouth opening of moderate width, peristome nearly equal lobed. 



Dimensions. — Height, two fifths of an inch ; breadth, nineteen twentieths of an inch. 



Formations. — " Portlandien moyen, Kimmeridgien, du Spielberg (Hanover), de Fritzow 

 en Pomeranie." — Desor. 



Collections. — Museum Neuchatel. Coll. Roemer, my Cabinet. Sent me by Professor 

 Roemer. 



Hemicidaris mitra. Agassiz, Echinoderm. Foss. Suisse, II, p. 48, t. 17, figs. 7 — 9. 



Test hemispherical, inflated towards the base. Ambulacra prominent and nearly 

 straight, semi-tubercles small. Inter-ambulacral tubercles more crowded together than in 

 Hemicidaris intermedia ; areolas all confluent. Peristome deeply notched, and nearly 

 equal lobed. 



Dimensions. — Height, seven tenths of an inch ; breadth, one inch. 



Formations. — " Portlandien moyen (Calcaire a Tortues) de Saint Nicolas ores Soleure 

 Pterocerien de Pierre-Percee (Jura) assez rare." — Desor. 



Collections. — Museum Neuchatel. Coll. Thurmann. 



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