120 
PALAEONTOLOGY OF NEW YORE. 
exposed part of the volution. The casts are quite smooth and even, with the 
exception of the angular or subcarinate aspect of the dorsum upon a part of 
the outer volution. 
The figures 9-14 of plate 25 are from gutta-percha impressions in molds of 
the exterior of the shell. A few individuals preserve a portion of the shell, 
sufficient to identify the surface-markings; but by far the larger number are 
casts of the interior, preserving some portion of the shell in a crystalline 
condition. The figures on plate 26 illustrate the species as it occurs in casts, 
and with the imperfectly preserved shell. A single example, of unusual size, 
has the exterior of the shell nearly removed by maceration and solution, but 
still preserving some of the surface-markings. The specimen, figure 19, jfiate 
26, is one which has been subjected to maceration and a solution of the 
superficial portion of the shell, leaving a smooth surface, so far as the ordinary 
markings are concerned, but which has not quite the condition of a cast of the 
interior, though scarcely differing therefrom, except in the preservation of the 
dorsal carina. On the recurved portions of the volution some faint remains of 
pustules are visible, and another specimen in the same association is quite 
pustulose. 
This species occurs in the central portion of the Chemung group somewhat 
rarely, but in the higher beds it is abundant at one or two localities. In its 
surface characters it is quite distinct from any other species in the formations 
under consideration, but resembles in a great degree the B. tuberculatus of Fer- 
ussao and d’OrbignyA 
Formation and localities. In the slialy beds of the Chemung group at Phil- 
ipsburgh, Allegany county, N. Y., and in sandstone below the conglomerate 
near Mansfield and Tioga in Pennsylvania; at Howard in Steuben county, 
and abundantly at Nichols, Tioga county, N. Y. 
* Belleroplion tuberculatus, Ferussac & d’Orbigny. Monogr. Cephal., pi. 8, Figs. 7-10. 
“ “ d’Archiac & de Verneuil. Rhenish Provinces, p. 353, pi. 28, Fig. 9. 
“ “ Keyseri.tng. Petchora-land, 262, Taf. 11, Fig. 5. 
“ “ Geinitz. Grauwackenformation in Sachsen, Hft. ii, S. 44, Taf. 11, Fig. 12. 
“ “ Sandberger. Scliichtensystem in Nassau, S. 181, Taf. 22, Fig. 9, 9a, 9b. 
