GASTEROPODA OF THE LOWER GREEN MARLS. 53 



angle of nearly 90°, with the body volution proportionately large. Volu- 

 tions four and a half to five in number, ventricose, the upper ones rounded 

 on the exposed parts, even in the cast, with distinct, deeply marked sutures; 

 body volution somewhat shouldered on the top, but not flattened; below it 

 is short and very rapidly diminishing, so as to produce nearly a straight 

 line from just below the point of greatest diameter to the margin of the 

 cavity left by the removal of the columella or axis of the shell; aperture 

 imperfect in form, but as seen by the section of the cast must have been 

 acutely ovate, sharply pointed below and gradually widened upward for 

 about two-thirds of its length, and rounded at the upper end; columella, as 

 shown by the axial cavity, large and smooth, without folds or ridges; 

 surface marked by numerous vertical folds, about eight of which may be 

 counted on the outer half of the body whorl; these not seen on the cast 

 below the point of greatest diameter, indicating their absence on the lower 

 part of the volution in the living shell; no remains of spiral lines preserved 

 on the specimen. 



This species is readily distinguished from the others herein described as 

 casts by its ventricose and rounded volutions, more numerous vertical folds, 

 shorter spire, and short dwai-fish appearance as regards height. It is more 

 easily mistaken for a form of Pyropsis, perhaps; but, as compared with any 

 of those herein described, differs in the more rounded volutions and more 

 numerous vertical folds. The form of the lower half of the body whorl 

 and that of the margin of the axial cavity will readily distinguish them on 

 comparison. 



Formation and locality: Collected from the ferruginous layers of the 

 Lower Green Marls, at MuUica Hill, New Jersey, and furnished by Mr. 

 Joseph McFarland, of Philadelphia. 



Pyripusus pyruloides. 



Plate IV, Figs. 12, 13. 



Bapa pyruloidea Gabb: Proc. Acad. Nat. Sci., Phila., 1860, p. 94, PI. ii, Fig. 4; 



Synopsis, p. 74; Meek, Check List Cret. and Jur. Foss., p. 21. 

 Bapa pyruloidea? (Gabb) Meek: Geol. N. J., Newark, 1868, p. 730. 



This species was described by Mr. Gabb from a single imperfect cast 

 which is now in the collection at the Academy of Natural Sciences at Phil- 



