94 SUBCAIIBONIFEUOUS PEIUOD. 



MOLLUSCA VERA. 



Class CONCHIFERA. 



Oedee DIMYARIA, 

 Family CAIlDIIDiE(?). 



Genus CONOCARDIUM Brown, 1835. 

 Conocardium {?). 



From -strata of the Subcarboniferous period below Opliir City, Utah, a 

 single example of a species of Conocardium was obtained. It is too imper- 

 fect for full specific determination, but its observable characters indicate that 

 it belongs to an undescribed species. It is similar in size and also in many 

 of its details to C. trigonale Hall from the Corniferous limestone of New 

 York and Ohio. The costae and interspaces, as well as the very fine con- 

 centric striae that mai'k the surface, are very similar to those of that species, 

 but our shell differs in its smaller and more numerous costae, in being less 

 produced at the antero-ventral angle, and in the more distinct rounding of 

 the antero-lateral ridges. 



In case the discovery of more perfect specimens should confirm the 

 opinion that this shell belongs to an undescribed species, I propose for it the 

 name of C. semiplenwn. 



Class GASTEROPODA. 



Subclass DICECA. 

 Order RHIPHIDOGLOSSA. 



Suborder PODOPHTHALMA. 



• Family EUOMPHALID^. 



Genus EUOMPHALUS Sowerby, 1815. 

 Euomphalus luxus, White. 



Plate V, fig. 13 rt aud b. 



Shell of medium size, subdiscoidal, the spire being only a little 

 elevated ; volutions four or five ; outer side of volutions convex below but 



