GASTEROPODS. 153 



Shell rather large, heavy, subglobose, only slightly ex- 

 panded toward the aperture ; volutions regularly rounded, the 

 last with three low, broad, longitudinal folds, which are often 

 more or less nodose. Surface, excepting the last half of the 

 body whorl, marked by narrow, rather well-defined longitudinal 

 ridges. 



. Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures: Kansas City. 



Bellerophon percarinatus CONRAD. 



Plate 1, figs. 2a-f. 



Bellerophon percarinatus Conrad, 1842: Jour. Acad. Nat. Sci., Phila., vol. 



VIII, p. 268, pi. xvi, fig. 5. 

 Bellerophon percurinatus Norwood and Pratten, 1855: Jour. Aad. Nat. 



Sci., Phila., (2), vol. Ill, p. 74, pi. ix, fig. 4. 

 Bellerophon percarinatus Meek, 1872: U. S. Geol. Sur. Nebraska, p. 227, 



pi. iv, figs. 15a-b. 

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



Rep , pt. ii, p. 158, pi. xxxiii, figs. 9-14. 



Bellerophon perca?inatus Keyes. 1888: Proc. Acad. Nat. Sci., Phila., p. 234. 

 Bellerophon percarinatus Keyes, 1891 : Johns Hopkins Univ. Circulars, vol. 



XI, p. 29. 



Shell of medium size, subglobose, broadly expanded toward 

 the aperture ; umbilicus closed ; outer lip thin medially, much 

 thickened at the sides; callous portions of the inner labrum 

 quite thick. Last whorl marked by large transverse folds or 

 wrinkles, each of which has a prominent nodosity in the mid- 

 dle, the entire series resembling a prominent median ridge. On 

 each side of the central nodose elevation is another series of 

 more or less conspicuous nodes, giving to the shell a distinct 

 Iricarinate aspect. The surface is otherwise ornamented only 

 by lines of growth, which not unfrequently are somewhat im- 

 bricated. 



Horizon and localities. Upper Carboniferous, Upper Coal 

 Measures: Kansas City. 



