301 PALAEONTOLOGY OF NEW-YORK. 
Fig. 4. The exterior of a. large cast from the same rock, probably the Platyceras ex-pansies 
of Conrad (Annual Report of 1841, p. 56). 
In the earlier progress of this volume, the specimens figured on Plate lxvii, from 
the Upper Pentamerus limestone, were the only ones known to me in the Lower 
Helderberg group. Subsequently two or three species have been obtained from 
Becraft’s mountain, one of which is figured on Plate lv. 
Stropliostylus clegans (n. s.). 
Plate LV. Fig. 1 a , b, c, d. 
Shell obliquely ovoid. Spire short, very neatly tapering to a minute apex: 
volutions about four, symmetrically rounded on the exterior surface; 
suture neatly defined, the last volution ventricose, the upper or right 
margin of the lip much extended upon the side of the volution : aper¬ 
ture obliquely oval or ovoid. Surface marked by fine equal curving strife. 
The aperture has not been observed in this species; but from its general form and 
surface markings, I can have no doubt that its proper place is among the species of 
this genus. 
Fig. 1 a. A small specimen which is imbedded in limestone. Fig. 1 b. A larger individual. 
Fig. 1 c. A larger specimen, the surface better preserved. 
Fig. 1 d. An enlarged figure, showing more distinctly the fine striae and form of the shell. 
Geological -position and locality. In the compact beds of the shaly limestone : 
Helderberg mountains, Schoharie, and Becraft’s mountain near Hudson. 
