74 pal^o:n^tology of new jersey. 



recurved, narrowing posteriorly and flattened on the surface. Hinge-line 

 straight, short, not more than one-fourth the length of the shell in grown 

 individuals; posterior wing only moderately elevated, and the posterior 

 margin rapidly sloping backward from its extremity to the body of the 

 shell, anterior wing very slight, the anterior end of the shell being squarelv 

 truncate at right angles to the hinge. Beak of the shell small and terminal, 

 elevated above the wing and continuing in a ridge to the surface of the 

 valve. Greatest width of the shell opposite the posterior extremity of the 

 hinge. Surface of the shell lamellose, and marked by numerous concentric 

 varices of growth, and on the basal portion of the right valve indications 

 of fine radiating lines occur. Hinge area moderately wide, marked by 

 several transverse ligamental pits, arranged at a little more than one-fourth 

 of an inch apart, and also by numerous obHque corrugations. Muscular 

 imprints large and obliquely situated. Substance of the shell highly 

 nacreous throughout and iridescent. 



This species was originally described from Tippah County, Mississippi, 

 but has been recognized by its author and others as occurring in the Cre- 

 taceous strata of New Jersey. 



Formation and locality.— Th^ only examples of the species which I 

 have seen are from the marls of the lower beds at Woodbury, Gloucester 

 County, New Jersey, and appear to be quite abundant, but usually in a 

 very fragmentary condition. Mr. Conrad's specimens were from Tippah 

 County, Mississippi. 



Gervilliopsis minima, u. sp. 

 Plate XV, Fig. 7. 



Shell small, the only specimen observed, a cast, measuring only a trifle 

 over one inch in length, and less than three-eighths of an inch in its greatest 

 width. Shell elongate-elliptical, extremely oblique, slightly curved, and 

 the valves very ventricose. The beaks, as shown on the cast, have been 

 pointed, the area wide, and the anterior hiatus has been proportionallv 

 large and distinct. . The muscular scars are very distinct and well marked. 



The cast is a miniture of G. ensiformis, except in its greater ventri- 

 cosity, and were it not for that feature would very naturally be taken for 

 a young individual of that species. All the small shells which I have seen 



