SUBCAEBONIFEROUS PERIOD. 95 



flattened a little above so as to form a more or less distinct angle witli the 

 flattened upper side ; under side regularly and continuously rounded from 

 the outer side into the umbilicus, where it meets the next volution within ; 

 suture distinct ; umbilicus moderately deep and broad. Surface marked by 

 distinct lines and occasional corrugations of growth. Diameter of coil of 

 the largest specimen in the collections, thirty-eight millimeters. 



This species resembles JE. latus Hall, the type-specimens of which were 

 obtained from the Burlington limestone division of the Subcarboniferous 

 group at Burlington, Iowa, and Quincy, Illinois. The specimens of tlie 

 collection present differences from the typical forms of the species which I 

 at first regarded as only varietal, but upon further examination I consider 

 them specific ; the principal of Avhich differences are their smaller size, 

 less rapidly increasing volutions, and the absence of the elevation, or 

 incipient fold, upon the upper side of the volutions adjacent to the suture 

 which characterizes E. latus. 



Position and locality. — Strata of the Subcarboniferous period ; below 

 Ophir City, Utah, and also "near the base of the anticlinal", at Opliir 

 City. 



