



130 ■ Organic Remains of the 



Found in New Jersey, and generically mentioned in the former 



part of this Synopsis 



PECTEN. 



P. membranosus. (S. G. M.) PL X, fig. 4. 



Convex, thin, with nearly an hundred delicate costae, the alternate 

 ones being smaller. Diameter three fourths of an inch. 



Found by Mr. Conrad in the calcareous strata of South Carolina. 



P. calvatus. (S. G. M.) PL X, fig. 3. 



Orbicular, thin, smooth, with obsolete radiating lines. Diameter 

 three fourths of an inch. 



Occurs with the preceding species. 



OSTREA. 



O. torosa. (S.G.M.) PI. X, fig. 1. 



Elongated, with strong squamous longitudinal costae. Length four 

 and a half inches. 



m 



Occurs in the blue marls of New Jersey. This is species No. 3 

 of the former part of this Synopsis. 



O. radians. (Conrad.) Fossil Shells, PL 13, Jig. 1. 



Oblong, compressed, lobed and flexuous on one side ; ribs numer- 

 ous, radiated. 



From the calcareous strata of the Southern states. 



O. sellaformis . (Conrad.) Fossil Shells, PL 13, Jig. 2. 



Oblong, convex, thick and ponderous, lobed ; one side of the 

 larger valve profoundly sinuous, and the opposite side gibbous. 



This and the preceding species were described by Mr. Conrad as 

 tertiary fossils ; but the recent investigations of that geologist prove 

 them to be characteristic of the calcareous secondary strata of the 

 Southern states. 



TEREBRATULA. 



T. lachryma. (S. G. M.) PL X, fig. 11. 



Ovato-triangular ; beak produced, foramen large; both valves 

 marked by delicate longitudinal striae Length half an inch. 



From the calcareous strata of South Carolina. 



T. Harlani. (S. G. M.) 



Var. discoidal. PL IX, fig. 8. 



This remarkable variety occurs with the ovoidal and rectilateral 

 forms at Ralph's Mills, Burlington Co. N. J. 



Var. rectilateral. PL IX, fig. 9. 



The sides of this variety are often nearly parallel. 



