aa» PALiEONTOLOGY OF NEW-YORK. 



Platyceras incile ( n. s.). 



PtATE 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 mearly 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. 



t*latyceras tubseforme ( a. s.). 



Plate LXIII. Fto. 11. 



§HELL 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. 



ScbfAce matked 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 

 pi*eceding, to which it bears some general resemblance. 



