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 carinse 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 striae 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 carinse, 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. Sci., Phila., and 

 Am. Mus. Nat. Hist, New York City. 



VOLUTID^. 



VOLUTODERMA AbBOTTI. 



Plate XXI, Figs. 4-9. 



Volutilithes Ahhotlii Gabb : Proc. Acad. Nat. Sci., Phila., 1860, p. 94, PL ii, Fig. 7 ; 



Synopsis, p. 93. 

 Volutilithes {?) Ahhottii Gabb : Meek, Check List Cret. and Jur. Foss., p. 21 ; Geol. 



N". J., Newark, 1868, p. 739. 

 Volutomorpha Abbottii Gsih\) : Proc. Acad. Nat. Sci., Phila., 1876, p. 393. 



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 hiplicata Gabb, unless we restrict both species to the type specimens. 



