FOREIGN OOLITIC PSEUDODIADEMAS. 139 



Test circular, much depressed on the upper and under surfaces ; tubercles nearly the 

 same size in both areas ; areolas surrounded by a circle of granules ; four rows of small 

 secondary tubercles between the peristome and the equator ; mouth opening of moderate 

 width ; peristome not deeply notched. 



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

 nine twentieths. 



Formation. — " Corallien inferieure (Terrain a chailles) du Fringeli (Canton de Soleure), 

 de Nantua, des environs de Salins, de Druyes (Yonnc)." Desor. 



Collections. — Museum Neuchatel, Coll. MM. Gressly, Marcou, Cotteau. Common. 



Pseudodiadema Orbignyanum, Cotteau. Syn. Diadema Orbignyanum, Cotteau, 



Echinides Foss., tab. 17, fig. 2 — 6. 



Test circular hemispherical, flattened at the base, and depressed on the upper surface ; 

 ambulacra narrow, with two rows of primary tubercles ; inter-ambulacra with two rows of 

 primary tubercles, and six or eight rows of small equal-sized secondary tubercles ; the 

 primary tubercles of both areas are about the same size ; those of the inter-ambulacra arc 

 closely surrounded by numerous secondary tubercles ; apical disc small, genital plates 

 narrow; poriferous zones narrow; pores falling into triple oblique pairs near the mouth, 

 but strictly unigeminal above ; mouth opening large ; peristome deeply notched ; lobes 

 very unequal. 



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

 seven tenths of an inch. 



Formation. — Corallien de Coulanges sur Yonne, Druyes, et Chatel-Censoir, (Yonnc), 

 Profont (Ain), Hobel (Canton de Soleure). 



Collections. — Museum Bale, Coll. MM. Cotteau, Renevier. Plaster mould, my 

 Cabinet. 



Pseudodiadema tetragramma, Agassiz. Syn. Diadema tefragramma, Agass., Echinod. 



Foss. Suisse, tab. 17, figs. 3 ( J — 4:3. 



Test circular, hemispherical, depressed ; inter-ambulacra with four rows of secondary 



