FOREIGN OOLITIC HEMICIDARIS. 103 



Hemicidaris diademata. Agassiz, Echinoderm. Foss. Suisse, II, p. 49, t. 19, 



figs. 15—17. 



Cotteau, Etudes Echinides Foss., p. 128, t. 14, figs. 1 — 5. 



Test hemispherical, sub-inflated below, and depressed at the upper surface. Ambulacral 

 areas straight, wide and expanded below to enclose six pairs of large serai-tubercles ; 

 narrow above, with four rows of small granules; more or less irregularly disposed. Inter- 

 ambulacral areas with two rows of tubercles, which are large and prominent at the equator, 

 but are very small, and become suddenly dwarfed, on the upper surface. Apical disc 

 large. Mouth opening large ; peristome deeply notched, divided into ten nearly equal- 

 sized lobes. 



Dime?mo)is. — Height, seventeen twentieths of an inch ; breadth, one inch and four 

 tenths. 



Formations. — " Portlandien inferieur ? Astartien de la Vallee de la Birse, de Porrentruy, 

 du Jura Soleurois, rare." — Desor. 

 " Hobel, Soleure." — Michelin. " Corallien etage Driiges, Yonne." — Coti. 



Collections. — Museum Neuchatel. Coll. Michelin, Cotteau, Wright. 



Hemicidaris stramonium. Agassiz, Echinoderm. Foss. Suisse, II, p. 47, t. 19, figs. 



13, 14. 



Test small, thick, sub-spheroidal. Ambulacral areas narrow and flexuous, with six or 

 seven large, prominent semi-tubercles, extending in a zigzag line to near the circum- 

 ference : upper part of the area with two marginal rows of small granules. Inter-ambulacral 

 areas with six tubercles in each row; the bosses are large and prominent and the 

 tubercles are large, especially on the upper part of the test. " Spines cylindrical, with 

 a prominent milled ring, without a distinct neck ; surface covered with small sporadic 

 granules ." — Desor. 



o 



Dimensions. — Height, three fifths of an inch ; breadth, nine tenths of an inch. 



Formations. — Portlandien inferieur (Astartien) de Delemont, Raedersdorf, Pfeffingen, 

 de Chablis (Yonne). 



Collections. — Museums Neuchatel, Zurich, Bale. Coll. MM. Michelin, Cotteau. 



The specimen in my Cabinet, sent by M. Michelin, is from Le Loile pres 

 la chaux de fonds Neuchatel. 



