308 3Ionograph of the Gasteropoda. 



Found at Riehnioiid, Indiana, near the upper part of the Cmcinnati 

 Group, Confined, probably, to a range withm fifty feet of the Upper 

 Sihn-ian fin-mation. Casts only are found. 



Bucania costatus — (James, 1872). 



&' 



Shell thin, composed of two and a half to three rapidly enlarging 

 rounded volutions, the inner of which are contiguous, or possibly very 

 slightly embracing, while the last half turn becomes a little discon- 

 connected from the others ; umbilicus rather large and deep ; dorsum 

 rounded, and without any traces of a keel ; aperture nearly circular, 

 slightly sinuous on the dorsal margin. Surftice ornamented by dis- 

 tinct, raised, revolving lines, or costse, which increase in number by 

 the intercalation of smaller ones between the others, as the shell in- 

 creased in size, so as to present an alternately larger and smaller 

 series, or, at some stages of growth, showing three smaller between each 

 two of the largest, in which case the middle one of the smaller three 

 is usually a little larger than the other two; crossing the whole, thin, 

 raised laminae of growth generally occur, at irregular distances, and 

 between these, numerous minute, crowded, transverse strise may be 

 seen, by the aid of a magnifier. 



Greatest diameter, about 0.84 inch ; convexity of the body volution, 

 about 0.54 inch. 



Mr. James placed this species in the genus CyiioUfes, and Professor 

 Meek followed Oyrtolites, with the interrogation point of ignorance, 

 and while I am not sure that they are not both right, I, nevertheless, 

 believe it belongs to the genus Bucania, in which I have placed it. 



I found one specimen on the top of the hill back of Cincinnati, at 

 an elevation of about 400 feet above low water-mark; other specimens 

 have been found in the vicinity of Morrow^ in Warren county, at a 

 little greater elevation. It is considered a very rare species. 



Genus Cyrtolites — (Conrad, 1838). 



\_Etyin. — Kiirtos, curved; I'dhos, stone.] 



Shell thin, symmetrical, horn-shaped or discoidal, with whorls more 

 or less separate, keeled and sculptured. 



Cyrtolites oriiatus— (Conrad, lS38j. 

 Convolute; sj)ire equally depressed on either side; volutions, two or 



