GASTROPODA— BELLER0PH0NTID2E. 



621 



Coal measures of Illinois, Indiana, Ohio, Pennsylvania, Arkan- 

 sas, Missouri, and Nevada ; Permic of Texas. 

 60. B. percarinatus Conrad. (Fig. 834, a-c, d-f.) Carbonic. 



Medium-sized, rapidly expanding, non-umbilicated ; outer lip 

 laterally thickened ; dorsum with three rows of nodes, the median 

 one most prominent, the lateral ones dying out as ribs. A variety 

 with the lateral nodes obsolete occurs with this (Fig. 834, a-c). 



FlG. 834. a-c, Bellerophon percarinatus var. j3 ; d-f, B. percarinatus ; g, h, Buca- 

 nopsis montfortianus. (After White, 13th Ind. Rep. and Bull. 77, U. S. G. S. )] 



Coal measures of Nebraska, West Virginia, Pennsylvania, Ohio, 

 Indiana, Illinois, Iowa, Missouri. 



XX. Euphemus McCoy. (Emend. Waagen.) 

 Closely involute, subglobose, Bellerophontid shells, not ab- 

 ruptly expanded, and with wide, but generally obscure band ; 

 inner lip with low parallel columellar folds or ridges, often extend- 

 ing as a thin covering over the greater part of the preceding whorl, 

 giving a part of the shell a strongly striate aspect. Carbonic- 

 Permic. 



61. E. carbonarius (Cox). (Fig. 835, a-c.) Carbonic. 

 Small, globose, with broadly rounded dorsum, and transversely 



compressed sublunate aperture, without expanded lip ; band ob- 

 scure, sometimes concave ; surface, except on final portion of last 

 whorl, with 18-25 strong revolving lines, nodose near the um- 

 bilicus. 



Coal measures of West Virginia, Ohio, Kentucky, Indiana, 

 Illinois, Iowa, Missouri, Kansas, Nebraska, Arkansas, and Texas. 



62. E. nodocarinatus. (Fig. 835, d, e.) Carbonic. 



