﻿NEW CRETACEOUS FOSSILS. 303 



S. G. M., but is invariably smaller and differs a little in shape. The specimen figured 

 is larger than the average. 



Localities. — Monmouth and Burlington Cos., N. J. My collection. 



C. Delawarensis. PI. 48, fig. 21. Shell subquadrangular; beaks and umbones 

 small ; umbonal ridge smaller than in the preceding species and rounded near the 

 posterior end, slightly curved upwards toward the cardinal margin ; muscular im- 

 pressions deep ; anterior edge rounded, basal gently sinuous, posterior subquadrangular 

 (in the cast) ; shell concentrically striated. 



This species differs from the preceding in being proportionally longer, in having 

 smaller umbones, the umbonal ridge is smaller, more rounded, and loses itself towards 

 the end in the general curve of the shell, while in C. Monmouiliemis it continues 

 uninterruptedly to the extreme edge of the shell, abruptly angular. There is besides 

 in the cast of the present species, a small supplementary ridge on the cardinal side of 

 the umbonal ridge, which is not found in the other species. 



Locality. — Deep Cut, Delaware and Chesapeake Canal. 



CARDITA, Brug. 



C. subquadrata. PL 48, fig. 22, a, b. Shelf subquadrate ; beaks small, curved 

 anteriorly ; umbones broadly rounded ; surface marked by about twenty compound, 

 radiating ribs, each consisting of a broad rib, surmounted by a smaller ridge. 



Locality and position. — Green marl, Burlington Co., N. J. W. Cleburne. Collection 

 of the Academy and my collection. 



LEDA, Solium. 



L. pinnaforma. PL 48, fig. 23. Shell subtriangular ; beaks incurved ; umbones 

 large, prominent ; umbonal ridge small and faint ; anterior side rounded, posterior 

 acuminate, base broadly rounded ; surface marked by numerous, prominent, concen- 

 tric lines. The figure is twice the linear size of the specimen. 



Locality and 'position — With the preceding. Collection of the Academy. 



L. protexta. PL 48, fig. 24. Shell elongated, narrow, wider near the beaks; 

 beaks small, posterior end long, narrow and apparently curved slightly upwards. A 

 cast. 



Locality and position. — With the preceding, and from Gloucester Co., N. J. Collec- 

 tion of the Academy. 



CULTELLUS, Con. 



C. oretaceus. PL 48, fig. 25. Shell elongated ; beaks small and placed near the 

 anterior end ; basal margin regularly curved ; anterior muscular impressions well 



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