152 GASTEBOPODS. 



Shell with inner whorls small, outer one broadly expanded ; 

 band narrow, well defined and slightly elevated in the center 

 of a rather deep, longitudinal depression ; umbilicus closed. 

 Aperture ample, transversely reniform ; outer lip very thin 

 medially, but becoming greatly thickened toward the umbilical 

 parts ; sinus moderately deep ; inner labrum callous. Surface 

 marked by fine raised longitudinal lines, about every fourth 

 one of which is much more prominent than the others; these 

 are crossed by many minute striations parallel to the lines of 

 growth. With the exception of the expanded portion of the 

 shell, the volutions are also ornamented by large nodose ridges 

 extending from the median depression to the umbilicus on each 

 side. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures: Kansas City. 



Bellerophon stevensianus MCCHKSNEY. 



Bellerophon stevensianus McChesney, 1860: Desc. New Pal. Foss.,p. 61. 

 Bellerophon stevensianus McChesney, 1867: Trans. Chicago Acad. Sci., 

 vol.1, p. 46, pi. ii, fig. 18. 



Shell small, somewhat compressed, gradually expanding ; 

 band rather narrow, forming a prominent medial ridge, which 

 is bordered on each side by a slight depression ; aperture some- 

 what semilunate ; outer lip thin, much thickened toward the 

 umbilical regions. Surface marked by prominent lines of 

 growth. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures : Kansas City. 



Bellerophon nodocarinatus HALL. 



Plate 1, figs. 4a-c. 



Bellerophon nodocarinatus Hall, 1858 : Geology Iowa, vol 1, p. 725, pi. xxix, 



figs. 15a-c. 

 Bellerophon tricarinatus Shumard, 1858: Trans. St. Louis ^.cad. Sci., vol. 



I, p. 204. 

 Bellerophon inspeciosus White, 1882: U. S. Geog. Sur. w. 100 Merid., 



Supp. vol. in, App., p. xxx, pi. iv, figs. la-c. 

 Bellerophon nodocarinatus White, 1884 : Geol. Sur. Indiana, 13th Ann. Rep. 



p. 159, pi. xxxviii, figs. 3-5. 



