438 CRETACEOUS PALEONTOLOGY. 



1861. Ostrea panda Gabb, Synop. Moll. Cret. Eorm., p. 209 



(153)- 

 1864. Ostrea panda Meek, Check List Inv. Foss. N. A., Cret. 



and Jur., p. 6. 



1868. Ostrea panda Con., Cook's Geol. N. J., p. 724. 



1869. Ostrea panda Coquand, Monog. Gen. Ost. Terr. Cret., 



p. 57, pi. 30, figs. 8-9. 

 1884. Ostrea pmda White, 4th Ann. Rep. U. S. G. S., p. 298. 

 1886. Ostrea panda Whitf., Pal. N. J., vol. i (Monog. U. S. 



G. S., vol. 9), p. 30. 



Description. — Shell rugose, irregularly subovate in outline; 

 the dimensions of a nearly complete lower valve are: height, 

 21.5 mm; width, 26 mm.; free margins of the valves corrugated 

 by rather broad, rounded plications which do not extend to the 

 beak, those towards the cardinal margins becoming smaller; 

 shell also marked by more or lesg irregular concentric lines of 

 growth which are sublamellose upon some portions of the valve ; 

 beak rather sharply pointed and separated from the hinge-line 

 by a flat, triangular, cardinal area whose surface lies nearly at 

 a right angle tO' the general plane of the valve. The upper valve 

 not recognized in the New Jersey collections. 



Remarks. — This species was originally described from the 

 Cretaceous of Delaware, but has usually been identified by more 

 recent authors as a Tertiary species from the southern states. 

 Judging from the Delaware locality given by Morton, St. George, 

 the original specimens of the species must certainly have been 

 from the Cretaceous. A single lower valve is present in the 

 recent collections of the New Jersey Survey, which has been used 

 as a basis for the description given above. This specimen seems 

 toi agree in all essential characters with Morton's original de- 

 scription and illustrations of the species, and it is believed that 

 the identification is correct although the type specimens have 

 not been available for comparison. The writer has not had the 

 opportunity to^ determine the relationships of the southern Ter- 

 tiary shell which has been identified by authors as O. panda, but 

 it is altogether probable that it is a distinct specific form. 



