ORISKANY SANDSTONE. A'i 471 



The above description I suppose to indicate this species, it being the only one . 

 known to me in the Oriskany sandstone to which it is applicable. The shell is large, 

 obliquely subovate, preserving in the cast but two volutions, a third having doubt- 

 less existed in the entire shell. The spire, beyond the first volution, is extremely 

 small ; suture canaliculate : the aperture is nearly circular ( in a specimen some- 

 what compressed ); the columellar lip, on its outer margin, is strongly angulated, 

 and concave within. The ajierture is filled with stone, so that the inner edgeof Uie 

 pillar lip cannot be seen. 



This species is more expanded than the preceding, with a proportionally smaller 

 spire beyond the first volution. 



Fig, 2. A small specimen which is obliquely compressed. The peristome is extended around 

 the adjacent volution, giving it a difiFerent aspect from the other specimens of the 

 same species. 



Fig. 3 a. View of the aperture, showing its form, with the outer angle of the columellar lip. 



Fig. 3 b. View of the upper side of the spire and the expanded body volution. 



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

 harie counties. ^ 



StTophostylus iimtheri (n.s.). 



Plate CXVIII. Fia. 1 a, b. 



Shell obliquely ovoid or subglobose ; the spire elevated : volutions about 

 four, the last comprising almost the entire bulk of the shell. Aperture 

 subcircular, a little higher than wide : peristome continuous, thin, 

 joining the adjacent volution on the lower side or becoming free on the 

 posterior side, and joining the outer margin of the columellar lip. 

 Volutions very symmetrically decreasing : suture canaliculate ; the 

 depression deepening towards the last volution, till, in older forms, the 

 last volution is sometimes quite free at the aperture. 



Surface marked by fine transverse striae, which, in older specimens, 

 become towards the aperture elevated, lamellose, and imbricating. 

 This differs from either of the above described species, in its more elevated spire 



and the great height of the aperture, as well as the expansion of the peristome over 



the preceding volution, and the disjoining of this part in old shells. 



The specimen figured is imperfect, but presents in a pretty satisfactory manner 



the principal features of the species. Another specimen, of larger size, has an 



aperture of one inch and a quarter in height. 



Fig. 1 a. Profile view of the spire. 



Fig. 1 b. View of the aperture, which is imperfect in outline, the columellar side being 

 broken off. 



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



