GASTEROPODA OF THE LOWER GREEN MARLS. 81 
Formation and locality: In a blackish layer of the Lower Green Marls 
in Monmouth County, New Jersey, the exact locality not known. Collec- 
tion Acad. Nat. Sei., Phila. 
TURBINELLA ? SUBCONICA., 
Plate rx, Figs. 7 
Turbinella subconica Gabb: Proc. Acad. Nat. Sci., Phila., 1860, p. 94, Pl. 1, Fig. 
6; Synopsis, p. 86; Meek, Check List Cret. and Jur. Foss., p. 21. 
Turbinella ? subconica (Gabb) Meek: Geol. N. J.. Newark, 1868, p. 730. 
8. 
bf 
Shell rather below a medium size, the cast measuring only about 1 
neh 3 in height, with a transverse diameter somewhat less; form turbinate, 
with a very low spire, consisting of not more than three volutions in the 
only specimen known; volutions ventricose, obeonical, scarcely rounded on 
the upper margin, but rapidly narrowing below and rounded on the side; 
aperture large, almost semilunate, or only very slightly convex on the inner 
margin; columella strong, marked by two very distinct plications at the 
lower third of the aperture, the lower one being distinctly the stronger of 
the two; sutures between the whorls of the cast very large, indicating a 
thick, heavy shell; surface as shown on the inside of the body whorl of the 
cast marked by strong spiral lines or ridges, and by remarkably strong 
vertical folds, numbering twelve or thirteen on the last volution, and trans- 
mitting their features only very slightly to the internal cast at the point of 
greatest diameter, but showing on the inside as above stated for more than 
half its depth. 
This species has very much the appearance, in its condition as an 
internal cast, of a species of Rapa, but the columellar cavity is rather small 
for that genus. The plications on the columella, however, about which 
there is no shadow of doubt, at once remove it from that group and mark 
it as belonging to the Turbinellide. My. Gabb’s figure given in Proc. Acad. 
Nat. Sei., Phila. as above cited, is very poor, and much smaller than the 
type and only specimen, a figure of which is given full size and enlarged 
on our plate. | 
Formation and locality: In dark terruginous marls from the Lower 
Greensands in Monmouth County, New Jersey. The definite locality not 
known. Collection Acad. Nat. Sei., Phila. 
MON XVIII——6 
