FOREIGN JURASSIC STOMECHINI. 225 



opening very large, half the diameter of the test ; peristome pentagonal, the ten notches 

 wide and obtuse, with small lobes between. 



Dimensions. — Specimen figured by M. Agassiz : height, one inch and three quarters ; 

 transverse diameter, two inches and four tenths. 

 Specimen in my cabinet : height, one inch ; transverse diameter, one 

 inch and nine tenths. 



Formation. — Corallien infer. (Terrain a Chailles) de la Combe d'Echert (du Val de 

 Moutiers), de Salins. Corallien etage Commercey (Meurthe), Chatel- 

 Censoir, et Druyes (Yonne). 



Collections. — Museums Neuchatel, Bale, Porrentruy. Collection of M. Michelin. 

 British Museum, my cabinet. 



Stomeuhinus semiplacenta, Desor. Cotteau, Etudes sur les Echinides Foss., 



pi. 45, fig. 5. 



Test sub-circular, sub-inflated above, concave below ; ambulacra with four rows of 

 tubercles ; inter-ambulacra with ten rows of tubercles at the circumference, irregularly 

 disposed, diminishing on the upper surface ; tubercles of both areas nearly equal-sized, 

 and each surrounded by circles of granules ; mouth opening very large ; peristome 

 decagonal, notches very wide and deep. 



Dimensions. — Height, nine tenths of an inch ; transverse diameter, one inch and seven 

 tenths. 



Formation. — " Kimmeridge etage des environs de Chablis et Havre." Cotteau. 



Collections. — MM. Rathier, Royer. 



