GASTEROPODA OF THE LOWER GREEN MARLS. 101 
under his original description do not agree with those of this species, his 
shell being proportionally wider; but I can find no other one agreeing 
more nearly with it, so leave it as a synonym, since he so considered it him- 
self, and I have not been able to find his type; he had probably compared 
with Mr. Conrad’s original at the time he so placed it. | 
Formation and locality: In the Lower Green Marls at Mullica Hill, at 
Holmdel, and Monmouth County, New Jersey. Mr. Conrad’s specimen 
was from Tippah County, Mississippi. 
TURBINOPSIS ANGULATA, 0. Sp. 
Plate x11, Figs. 17, 18. 
Shell rather above the usual size, short conical, and rather obese in 
general form, oblique as seen from the back; composed of two and a half 
or three volutions, which increase somewhat rapidly in size with mereased 
growth; apical angle about 70°; volutions ventricose, obliquely flattened 
on the upper side and obtusely round-pointed below, with a quite distinct 
angulation at the upper third, or just above the upper third of the length, 
as seen on the last one, and a less distinct one below the middle, dividing 
the body volution into three sections, -of which the middle one is rather 
broader than the others and imperceptibly flattened; above the body volu- 
tion the whorls are marked by about eight vertical folds, or angulations rep- 
resenting folds, which do not extend to the suture line on the cast, the only 
condition in which it has been observed; aperture elongate ovate, largest 
below; columellar cavity in the cast of medium size, marked at the base 
by a distinct groove, indicating the presence of a tooth-like ridge on the 
shell, showing the generie position of the species; the surface has also been 
marked by spiral lines or ridges, fifteen or more in number, on the last 
whorl near the lip, very perceptible on the surface between the whorls in 
the cast. 
This species differs from any of the associated forms, by the angula- 
tions of the volutions, and in the proportional size and form of the volutions 
themselves. There is only a single authentically identified cast, and that 
one imperfect in the upper part of the spire, but its features are so very 
distinctive that it may readily be distinguished from any other species in 
the green marls. 
