72 PALEONTOLOGY OF NEW JERSeY. 



the most perfect one. The external features of the shell are not preserved 

 on any of the casts in full strength, but on the mside of the outer volutions, 

 where the inner one has left its imprint, they are shown in full strength, 

 and are quite strongl}- marked, both by spiral and by vertical ridges, which 

 become node-like at their intersection. The species is quite variable, and 

 it is rather difficult, among the imperfect material, to draw a line of divis- 

 ion between it and ]'. ponderosa herein described. It, however, has much 

 shorter and more compact upper volutions, which are more ventricose accord- 

 ing to their height, and the beak has also been much longer and more slen- 

 der. These featm-es will, I think, serve to distinguish them. 



Formation and locality: It is known only from the Lower Greensand 

 Marls. Mr. Gabb's type was from Crosswicks, New Jersey. They are 

 also known from Mullica Hill, Freehold, Holmdel, and the Neversink Hills, 

 New Jersey. 



VOLUTOMOEPHA PONDEEOSA, n. sp. 

 Plate VIII, Figs. 5, 6, and Plate ix, Figs. 13-15. 



. Shell large and moderately ventricose, attaining a length of 7 or more 

 inches, with a transverse diameter of nearly or quite 2^ inches; spire mod- 

 erately elevated, with depressed' convex whorls ; volutions five or more, the 

 last one forming nearl}' or quite three-fifths of the entire length, gently con- 

 vex throughout the upper three-fourths of its length and slightly narrowed 

 and extended in front; aperture long elliptical, acute above and naiTowed in 

 front; sutures between volutions only moderate ; surface, as seen on casts, 

 usually smooth, but sometimes showing both vertical and spiral ridges, while 

 on the surfaces between the volutions of the casts very distinct vertical and 

 spiral ridges appear. On one of the larger individuals the columellar lip 

 appears to have been considerably thickened, and to have been but very 

 faintly marked by a single fold, very obliquely placed; while on the upper 

 portion of its surface the ridges of the preceding volution have left their 

 imprint, appearing as nearly horizontal folds, though in reality being the 

 eff"ect of external markings. The single very oblique fold is placed very 

 near the base of the columella, and on some specimens appears only as an 

 angulation of the columella. 



