180 FOREIGN JURASSIC PEDINAS. 



Formation. — Abundant in the "Callovien etage de Chauffour (Sarthe)." Triger. 

 Collections. — MM. Mickelin, Desmoulins, Cotteau, de Loriere, Triger. My cabinet. 



Pedina sublevis, Agassiz. Echinoderm. Foss. Suisse, II, tab. xv, figs. 8 — 13. 



— — Cotteau. Etudes sur les Echinides Fossiles, pi. 26, figs. J — 6. 



— — Bronn. Lethsea Geognostica, dritte Auflage, tab. xvii, fig. 10. 



Test circular, shell extremely thin, equally depressed at both surfaces ; ambulacra with 

 two rows of small tubercles, spaced widely apart, and accompanied by secondary tubercles ; 

 inter-ambulacra three times as wide as the ambulacra, with two rows of primary, and four 

 rows of secondary tubercles nearly as large as the primaries ; tubercles of both areas 

 nearly of the same size, and placed wide apart ; poriferous zones rather wide, trigeminal 

 ranks very oblique below, nearly vertical above ; mouth opening small, peristome decagonal, 

 and deeply notched. 



Dimensions. — Height, seven tenths of an inch ; transverse diameter, two inches. 



Formation. — Corallien (Terr, a Chailles) des Ravieres pres de Locle, Val-de-Travers 

 (Jura Neuchatelo is). Desor. — Dans les couches calcareo-siliceuses de 

 Chatel-Censoir et de Druyes. Cotteau. This species is the most 

 abundant of the genus, and is widely distributed through the 

 Corallian stage of France, Germany, and Switzerland. 



Collections. — MM. Michelin, Cotteau, and in most Continental museums. British 

 Museum. 



Pedina Michelini, Cotteau. Etudes sur les Echinides Foss., pi. 23, figs. 2 — 4. 



Mould much inflated, and sub-pentagonal, slightly depressed at both poles ; inter- 

 ambulacra very wide, with a median depression ; ambulacra very narrow ; poriferous zones 

 very narrow, trigeminal ranks nearly straight; test unknown. This species is found 

 always as a siliceous mould. 



Dimensions. — Height, one inch and seven twentieths ; transverse diameter, two inches. 



Formation. — " Dans les couches calcareo-siliceuses de l'etage Corallien inferieur, a 

 Chatel-Censoir et a Druyes." Cotteau. 



Collections. — Abundant. My cabinet. 



