GASTEROPODA OF THE LOWER GREEN MARLS. 43 
Formation and locality: In the Lower Green Marls at Holmdel, New 
Jersey. Collected by the Rev. Dr. Reiley, and now in the collection at 
Rutgers College. 
PyYRoPsSIS NATICOIDES, n. sp. 
Plate 1, Figs. 5-?. 
Small, obliquely ventricose, broadly naticoid in form, with a low spire 
and rapidly increasing volutions, the last: one of which is more rapidly 
deflected downwards than the earlier ones and forms the great bulk of the 
cast, appearing in its outer third almost as if detached from the inner volu- 
tions of the shell, caused probably by the excessive thickening of the shell 
at the suture; the columella has been small and the aperture proportion- 
ally quite large, and of a semicircular form, more pointed below than 
above; volutions not more than two and a half in number; surface of the 
cast smooth, with the exception of a few: faintly marked vertical folds or 
wrinkles which show only on the inner or smaller third of the outer volu- 
tions, and may have been caused by closely arranged varices of growth, 
but they resemble the folds on a regularly plicated shell. 
The species is peculiar in its naticoid form and in the rapid deflection 
of the outer portion of the last volution. Had it not been for the form of 
the aperture and columellar cavity, the cast would be naturally looked 
upon as that of a Natica or Gyrodes. The appearance of vertical folds would 
scarcely answer for Natica, but as they occur on only a small area of the 
outer volution they may be deceptive in their meaning. The cast might 
answer equally well for that of a species of Rhizocheilus, and the deflections 
of the last whorl would also agree with some species of that genus, but I 
am not aware that any species of that form has been recognized as low 
down as the Cretaceous. It might also answer quite well for a species of 
Rapa. Dr. Stoliczka figures species of Rapa’ which are quite strongly 
marked with vertical folds, which would show on an internal cast much 
more strongly than do these. 
Formation and locality: The specimen bears no label of locality, but 
possesses all the features of casts from the ferruginous layers of the Lower 
eee 
Ind. Geol. Surv. Pal. Indica, Cret. Fauna South Ind., vol. 2, Pl. x11. 
