FOREIGN JURASSIC PEDINAS. 181 



Pedina Charmassei, Cotteau. Etudes sur les Echinides Eoss., pi. 24, figs. 1 — 3 ; pi. 25, 



figs. 1—3. 



Test large, extremely thin, sub-circular; hemispherical and inflated on the upper 

 surface, flattened on the under surface ; ambulacra with two rows of tubercles, as large as 

 those in the inter-ambulacra, set closely and regularly together, on the extreme margins of 

 the area ; the intermediate miliary zone covered with fine granulations, poriferous zones 

 wide, trigeminal ranks very oblique ; inter-ambulacra four to five times the width of the 

 ambulacra, with four rows of primary tubercles, which extend very regularly from the 

 mouth to the summit ; tubercles small, slightly developed, well spaced out, and 

 accompanied with secondary tubercles almost as large, and which form, at the inferior 

 surface, and towards the circumference of the test, some irregular rows, extending to 

 the upper surface ; mouth opening small, peristome divided by wide notches into ten 

 unequal lobes. 



Dimensions. — Height, two and a half inches ; transverse diameter, four inches and a 

 quarter. 



Formation. — " Dans les couches calcareo-siliceuses subordonnees au Coral-rag inferieur, 

 avec Pedina Michelini et sublevis presque toujours a l'etat de moule 

 interieur siliceux." Cotteau. 



Collection. — M. Cotteau, very rare ; plaster mould in my cabinet. 



Pedina aspera, Cotteau. Etudes sur les Echinides Foss. pi. 44, figs. 7 — 12. 



Test circular, thin, nearly equally depressed at both poles ; ambulacra with two rows of 

 marginal, well-spaced-out tubercles ; inter-ambulacra thrice as wide as the ambulacra, with 

 two rows of primary tubercles, larger and more developed than in other JPedinas, and 

 surrounded by areolas ; several secondary tubercles scattered over the surface of the plates ; 

 poriferous zones narrow, trigeminal ranks not very oblique ; mouth opening small, 

 peristome not deeply notched. 



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

 one tenth. 



