MIOCENE MOLLUSCA AND CRUSTACEA. 123 
line extending from the apex to the base of the shell; and in others a free 
lamella on one side only; while fully one-half of the entire diameter is firmly 
soldered to the inside of the shell; all grades between these two extremes 
may be found among them. 
There is but little question as to Calyptrwa pileolus of H.C. Lea being 
the young of this shell, and I think Hipponyx Bullii of Tuomey and Holmes 
is only the separated cup of this species. Among the shells from New 
Jersey there are several of the inner cups of the species which have been 
broken from the outside shell, and they present precisely the features of 
their figures given under the above name. 
Formation and localities: The species seems to have been pretty gen- 
erally distributed in the Miocene of Maryland and Virginia. In New Jersey 
it is found at Shiloh, Jericho, and Bridgeton in the gray marly material, and 
also in the Brown clays, and is quite abundant. I have in hand specimens 
from Rutgers College and the National Museum—the latter in collections 
made by Mr. Frank Burns. 
CREPIDULA FORNICATA?. 
Crepidula fornicata Say? Conrad: Say, Jour. Acad. Nat. Seci., Phila., vol. 2, 2d ser. 
p. 225; Tuomey and Holmes, Plioce. Foss. 8. Carolina, p. 110, Pl. xxv, fig. 9; 
Emmons, Geol. Surv. ‘N. Carolina, p. 276, Fig. 194(?); Conrad, Miocene Foss., 
Pl. xiv, fig. 10; Heilprin, Proc. Acad. Nat. Sci., Phila., 1887, p. 404. 
Crypta fornicata Conrad.: Proc. Acad. Nat. Sci., 1862, p. 569; Meek, Check List 
Miocene Foss., p. 15. 
Among the fossils of the New Jersey Miocene beds I have seen only 
a single imperfect cast that I could refer to this well-known living species. 
The form is that of a broad, much curved, and rather shallow individual, 
such as are the most abundant along our Atlantic shores. As the specimen 
represented only the internal cast, and none of the external features were 
preserved, I can not tell what these features were, or how they may have 
differed from those recent forms. In it the plate appears to be developed 
about as in the living form, and the size and curvature about as is repre- 
sented by Mr. Conrad’s figure given in the Miocene Foss., Pl. xiv, fig. 10. 
The specimen is in the chocolate-colored clay marls from near Bridge- 
ton, N. J., and belongs to the National Museum collection. 
