42 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 inside of the outer volutions, 
where the inner one has left its imprint, they are shown in full strength, 
and are quite strongly 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 J’. 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 features 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. 
VOLUTOMORPHA PONDEROSA, 0. sp. 
Plate vim, Figs. 5, 6, and Plate rx, Figs. 13-15. 
Shell large and moderately ventricose, attaining a length of 7 or more 
inches, with a transverse diameter of nearly or quite 24 inches; spire mod- 
erately elevated, with depressed convex whorls; volutions five or more, the 
last one forming nearly 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 narrowed 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 surtace the ridges of the’preceding volution have left their 
imprint, appearing as nearly horizontal folds, though in reality being the 
effect 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. 
