GASTEROPODA OF THE LOWER GREEN MAKLS. 73 



This is probably the largest Gasteropod of the Cretaceous formation 

 within the State. It very closely resembles V. Conradi Grabb, but is much 

 larger in its extreme. The volutions of the spire are proportionally much 

 longer and by far less ventricose, and none of them are shouldered at the 

 top as in that species. The beak is also less extended and stronger, while 

 the vertical folds appear to have been more closely arranged. 



Formation and locality: In the Lower Green Marls at Cream Ridge, 

 Holmdel, Freehold, Neversink, and Eastern Monmouth, New Jersey. Col- 

 lection of Rutgers College. 



YOLUTOMOEPHA GaBBI, n. Sp. 



Plate VII, Fig. 6, and Plate viii, Figs. 1-4 

 Shell of moderate size, attaining a length of about 3 J inches in the 

 largest specimens observed. Form robust, with a short conical spire, in 

 which may be counted about three volutions above the last one; body 

 volution forming about thi'ee-fourths of the entire length, ventricose above 

 and tapering below, with a rather graceful swell near the middle of its 

 length, and rather abruptly narrowed above to the suture, forming an angu- 

 lation at the top; surface marked by coarse, moderately distinct, vertical 

 folds, which are strongest near the angulation at the top of the volution, 

 and become faint or even obsolete near the lower end; also by more closely 

 arranged spiral lines which present a somewhat nodose appearance at their 

 junctions with the vertical folds. The columella, as shown on an internal 

 cast, has been very thick and strong, and provided with a single strong 

 oblique fold near the middle of its length. Aperture rather wide and more 

 than half as long as the shell. 



This species has many features in common with V. Conradi Gabb, but 

 is proportionally shorter and more robust, with a shorter spire and more 

 distant vertical folds, while the body volution is much larger above in pro- 

 portion to its length and very much more angular. 



Formation and locality: In the Lower Marls at Holmdel, New Jersey, 

 where the external features are preserved in the marls, and as internal casts 

 in a coarse, pebbly sand marl, quite ferruginous in character, at MuUica, 

 New Jersey. The latter specimen is in the cabinet of the Acad. Nat. Sci., 

 Phila., and the former at Rutgers College. 



