83 2 
PALAEONTOLOGY OF NEW-YORK. 
Platyceras incile (n. s.). 
Plate LXIII. Fig. 10, 12 & 13. 
Shell spirally ascending, with one or more minute close volutions at the 
apex, below which are one or two widely separated volutions : volu¬ 
tions below the apex rounded, gradually increasing in size to the aper¬ 
ture, which is round, scarcely expanded, with the peristome somewhat 
undulated. 
Surface marked by fine transverse striae, and a single depressed plication 
following the direction of the suture line to the aperture, near which 
are other obscure plications. 
This differs from the preceding species in its smoother aspect, and in having 
but a single depressed plication marking the extension of the volutions above the 
aperture. 
Fig. 10. The lower part of the shell, consisting of a single volution. 
Fig. 12. A specimen preserving imperfectly the apex and nearly two volutions below. The 
specimen is somewhat flattened from pressure. 
Fig. 13. A fragment which is probably the apex of a specimen of this species. 
Geological position and locality. In the shaly limestone of the Lower Helderberg 
group : Schoharie county, and Virginia. 
Platyceras tubsefomie (n. s.). 
% 
Plate LXIII. Fig. 11. 
Shell with the spire rapidly ascending; apex unknown : lower volutions 
free, rounded, gradually expanding above and rapidly expanding to¬ 
wards the aperture, which is broadly campanulate ; peristome reflexed. 
Surface marked by fine transverse striae, which are strongly lamellose 
towards the aperture. 
The upper part of the shell is broken off, and only a single volution from the 
aperture remains. The freedom from plications, the broader curvature of the volu¬ 
tions, and the broadly expanded aperture, serve to distinguish this species from the 
preceding, to which it bears some general resemblance. 
