HKiLPMN.] TERTIARY. 313 



Osfrea panzana Conrad. 



Conrad published this form as coming from California in the Pacific 

 Eailroad Reports, VII, p. 193. He regarded it as possibly the mature 

 shell of 0. sitbjecta. I ha^e seen no specimens of this species; nor is 

 it determinable from Conrad's figures. Gabb was unable to recognize 

 it among the collections of the California Survey. 



Ostrea percrassa Conrad. 



(Plate LXVII, Fig. 3.) 

 This Miocene form has hitherto beeu recognized only in New Jersey. 

 Conrad published it in his Fossils of the Medial Tertiary Formation, 

 page 50, Plate 25, Fig. 1. 



Ostrea seulptiirata Conrad. 



(Plate LXX, Fig. 2.) 

 From Virginia. Published in Fossils of the Medial Tertiary Forma- 

 tion, page 50, Plate XXV, Fig. 3. 



Syn. — 0. rirgimava var. Conrad (non Graelin) : Fossils of the Tertiary Forma- 

 tions, first edition, p. 28. 



Ostrea suhfalcata Conrad. 



(Plate LXVIII, Figs. 1, 2, 3.) 

 From Virginia. Published by Conrad in his Fossils of the Medial 

 Tertiary Formation, page 50, Plate XXV, Fig. 2. 



Ostrea subjecta Conrad. 



Reported as coming from California, and published in the Pacific 

 Eailroad Reports, VII, page 193. I have seen no specimens of this 

 species, nor is it determinable from Conrad's figure. Gabb was un. 

 able to recognize the form among any of the collections of the California 

 Survey. 



Ostera tayloriana Gabb. 



(Plate LXVII, Fig. 1, 2.) 

 From California. Published in Paleontology of California, II, p. 34, 

 Plate 12, Figs. GO, COa. 



Ostrea titan Conrad. 



Conrad published this large oyster in the Proceedings of the Phila- 

 delphia Academy of Natural Sciences, VI, page 199; the Journal of 

 the same (n. s.), IV, page 300, and the Pacific Eailroad Reports, VI, 

 pag(5 72. 



This is to my knowledge the most ponderous oyster found in the 

 United States. In certain of its forms it so closely resembles the O. 

 f/ingensis of Schlotheim as to be but barely separable from the common 

 European species. Like it, it also affects the long, the curved, and the 

 scooped forms, the space between the valves in the last case being very 



