OF THE UNITED STATES. 21 



is mostly yellowish white, considerably friable, and re- 

 plete with fossils, although the number of species hitherto 

 discovered is inconsiderable. Among these, the Ostrea 

 cretacea and O. panda occur also in the older cretaceous 

 deposits of Alabama. 



GEORGIA. 



The Ferruginous sand appears to abound near Sanders- 

 ville in this state, whence I have received a number of 

 specimens of the Belemnites Jimericanus, 



ALABAMA. 



This state presents a vast deposit of both strata, for a 

 knowledge of which I am wholly indebted to Mr. Conrad, 

 who informs me that the counties of Pickens, Bibb, 

 Greene, Perry, Dallas, Marengo, Wilcox, Lownes, Mont- 

 gomery, and parts of Clarke, Monroe and Conecuth, are 

 chiefly composed of the older Cretaceous strata. In 

 Clarke county the newer Cretaceous rock predominates. 



One of the most prolific fossil localities is Prairie bluff, 

 in Wilcox county, as will be seen in the course of this sy- 

 nopsis. The following diagram will convey an idea of its 

 strata : 



Feet. 



70 



Loam &,c. 



Ferruginous sand, generally indurated 

 with Exogyra, Gryphsea &c. 



Same deposit, in a friable state, with 

 abundance of Ostrea fdlcata. 



River bed. 



The older Cretaceous rock constitutes the long and per- 

 pendicular bluff at Demopolis, where it has been ascertained 



