GASTEROPODA. 
95 
inch to more than an inch and a half in diameter. The casts of the younger 
individuals are less acutely angular on the back than of the older ones. The 
specimens present little variation in their general or special features—the 
younger specimens usually preserving the distinct fascicles of fine striae, 
separated by a single slender sharp line, while in the older ones this regularity 
is not observed and the striae become crowded in ridges, especially towards the 
aperture. 
The species has a very limited geographical range, so far as observed no 
specimen having been found to the west of Schoharie county. 
Formation and localities. In the Schoharie grit, and in the Upper Helderberg 
limestone at Schoharie, and the Helderberg mountains. A single imperfect 
specimen has been found in the Oriskany sandstone. 
Bellerophon Pelops. 
PLATE XXII, FIGS. 7-13. 
Bellerophon (Bucania) Pelops, Hall. Descriptions of New Species of Fossils, etc., p. 28. 1861. 
“ “ “ Fifteenth Rep. N. Y. State Cab. Nat. Hist., p. 56. 1862. 
Bellerophon Pelops, “ Illustrations of Devonian Fossils: Gasteropoda, pis. 22, 25. 1876. 
Compare B. propinquus, Meek. Proc. Acad. Nat. Sci. Phil., p. 78. 1871. 
“ “ “ Geol. Surv. of Ohio. Palaeontology, vol. 1, p. 226, pi. 20, fig. 4, a, b. 1873. 
She'll subglobose. Body-volution ventricose and expanded at the aperture; 
umbilicus closed by a callus of the lip; outer lip with a moderate sinus 
in front and broadly rounded on each side, thickened and twisted at the 
umbilicus, with usually a thin callosity spreading over the columellar side 
of the aperture. Aperture transverse, broadly subreniform. 
Surface marked by a slender dorsal band, which appears either as a simple 
elevation or with sharply carinate margins; the entire surface orna¬ 
mented by fine subregular strife, which, rising from the umbilical region, 
curve gently forward, and then more directly transverse over the body of 
the shell, bending slightly backward as they approach the dorsal carina, 
in crossing which they make a gentle retral curve; the strife are usually 
stronger on the dorsal side, and fainter in the umbilical region. 
