GASTEROPODA OF THE MIDDLE GREEN MARLS. 173 
This is a well marked species and easily distinguished from any other 
shell in the Cretaceous beds of New Jersey; even when without the long 
beak the three very well marked carinze form a distinguishing feature, and 
the low sloping spire also is different from that of any other shell associated 
with it. The absence of surface or spiral striz on the specimen is by no 
means a certain indication that none have existed, as they are all internal 
casts, and in a matrix that would scarcely preserve them. Mr. Gabb does 
not mention, nor does his specimen show the small transverse nodes around 
the upper carinze, but on another example they are very easily distinguished. 
On the second specimen mentioned the apex of the spire is broken, but 
there is good evidence preserved to show that it was mammillated. 
Formation and locality: In the yellow limestone sand of the Middle 
Marls, at Timber Creek, New Jersey. In the State collection at Rutgers 
College, collected by Dr. N. L. Britton. Also Acad. Nat. Sei, Phila., and 
Am. Mus. Nat. Hist., New York City. 
VOLUTIDZ. 
VOLUTODERMA ABBOTTI. 
Plate xx1, Figs. 4-9. 
Volutilithes Abbottii Gabb : Proc. Acad. Nat. Sci., Phila., 1860, p. 94, Pl. u, Fig. 7; 
Synopsis, p. 93. 
Volutilithes (2?) Abbottii Gabb: Meek, Check List Cret. and Jur. Foss., p. 21 ; Geol. 
N. J., Newark, 1868, p. 729. 
Volutomorpha Abbottii Gabb: Proc. Acad. Nat. Sci., Phila., 1876, p. 293. 
Shell of medium size, elongately oval in general outline, with a very 
short spire and large body volution which forms nearly the entire bulk of 
the shell, and which is nearly evenly convex above and below the middle. 
Volutions about four in number; suture line not very distinct. Aperture 
long and narrow, rather more than two-thirds as long as the shell, and 
pointed above and below. Columella comparatively strong, marked by 
three or four very oblique folds of moderate strength. Surface of the shell 
unknown, all the specimens recognized being internal casts. 
There is considerable resemblance between this species and Voluto- 
derma biplicata Gabb, unless we restrict both species to the type specimens. 
