GASTEROPODA FROM BASE OF THE UPPER GREEN MARLS. 183 
Fig. 27), an Eocene species, but there can be no doubt of the correctness 
of the generic reference of that species, and the form of the columellar folds 
and canal of this one are equally satisfactory. I know of no eretaceous 
shell with which it can be counfounded, as the generic characters are too 
well pronounced to be mistaken. 
Formation and locality: In the green sands at the base of the Upper 
Green Marls of New Jersey, at Farmingdale, New Jersey. Collection at 
Rutgers College. Collected by Dr. Britton in 1884. 
VOLUTID. 
ROSTELLITES BICONICUS, 0. sp. 
Plate xxl, Figs. 10, 11. 
Shell moderately elongated, as seen in the conditions of internal casts, 
the only condition in which it is at present known. Spire elevated, consist- 
ing of about four or five volutions, the aperture, which is narrow, forming 
about two-fifths of the length of the entire cast. Volutions moderately 
convex, largest at or near the upper margin, indicating something of a 
square, shoulder-like upper surface for the perfect shell; below this angula- 
tion the upper volutions are slightly convex, and in the casts leaving very 
deep and strong sutures between the different whorls of the spire. Lower 
volution distinctly largest above and cone-like in shape, with a short col- 
umellar projection below; the lower half of the volution being more rapidly 
tapering than the upper, forms a slight angulation just below the middle. 
Columella strong and marked by four nearly equidistant oblique folds; the 
lower one of which is not more than once and a half as far from the base 
as the distance between each fold. Aperture very narrow, pointed above 
and, below; surface, as far as can be seen on the internal casts, showing no 
evidence of longitudinal folds or revolving lines; but the shell having been 
quite thick may not have preserved such features on the interior surface. 
This is one of the forms usually found among specimens labeled 
R. nasutus ; but it differs very strongly from that one in the proportional 
length of the body volution and in the form of the lip side of the aperture. 
In R. nasutus, as shown on specimens when the external form is preserved, 
