47a PALEONTOLOGY OF NEW-YORK. 



Stropliostylus andrewsi ( n. s.)- 



Platk CXVIIL Fia. 2. 



Shell somewhat semiovoid. Spire very slightly elevated above the last 

 volution, which is extremely ventricose : aperture subcircular, a little 

 higher than wide ; peristome very oblique to the axis of the shell, ex- 

 panding over the inner side of the previous volution, but not continuous 

 with the outer edge of the columellar lip, which is angular, the lip 

 short, and terminating abruptly below. 



Surface marked by fine equal striae. * 



This species differs conspicuously in its low spire, broader aperture, and short 

 abruptly terminating pillar-lip, from either of the species in this rock. 



Fig. 2. View of the aperture, columellar lip, etc. 

 The figure does not represent the aperture sufficiently circular or high. 



Geological position and locality. In the Oriskany sandstone : Cumberland, Md. 



Platyceras tortuosnni ( n. s). 



Plate CXIIL Fio. 1-5. 



Shell spirally ascending, making a little more than one free volution : 

 volutions widely separated, very gradually increasing in size towards 

 the aperture, which is scarcely expanded ; peristome very oblique. A 

 broad spiral fold sometimes marks the inner side of the spire. 



Surface unknown. 



The specimens are all casts, or preserve a very small portion of the shell, which 

 18 not sufficiently perfect to show tlie surface characters. 



This species is closely allied to P. spirale, but does not appear to have had a 

 contiguous volution at the apex, nor to be so distinctly si^irally plicatej while the 

 specimens show no marked expansion at the aperture. 



Fig. 1-5. Views of different individuals (which are more or less perfect), showing a 

 gradation in size. 



Geological position and locality. In the Oriskany sandstone : Albany and Scho- 

 harie counties. 



