MIOCENE MOLLUSCA AND CKUSTACEA. 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 Calyptreea 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 FORNTCATAf. 



Crepidula fomicata Say! Conrad: Say, Jour. Acad. Nat. Sci., Pbila., vol. 2, 2d ser. 



p. 225; Tuomey and Holmes, Plioc. Foss. S. Carolina, p. 110, PI. xxv, tig. 9; 



Emmons, Geol. Surv. N. Carolina, p. 2745, Fig. 194(f); Conrad, Miocene Foss., 



PL xlv, Eg. 10; Heilprin, Proc Acad. Nat, Sci., Phila., 1887, p. 404. 

 Crypta fomicata 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 xlv, fig. 10. 



The specimen is in the chocolate- colored clay marls from near Bridge- 

 ton, N. J., and belongs to the National Museum collection. 



