112 



MR. CONRAD'S DESCRIPTIONS 



Upper Eocene series, but as yet no fossil has been obtained from it identical with a 

 species of the Carolinas, Mississippi or Alabama, unless it is a specimen of Carcharias 

 megalodon, which Captain Powell, of the Navy, found on the bay shore. 



The only species of Crassatella which occurs at Vicksburg, is more nearly related 

 to C. tumida of the Paris basin than to C. alia of Claiborne. 



Ostrea sellaformis characterises the lower division of the Eocene formation. It 

 occurs abundantly beneath the fossilliferous sands of Claiborne ; at Vance's Ferry, 

 South Carolina; and on the right bank of James river, below City Point, Virginia. 

 I also refer to this section, the localities at Fort Washington, Piscataway, and Upper 

 Marlborough, Maryland. Other characteristic fossils are Cardita planicosta, and 

 Turritella Mortoni, the former occurring at Piscataway ; at Claiborne, Alabama ; and 

 also at Marlbourne, on Pamunkey river, Virginia, the residence of Edmund 

 Ruffin, Esq. 



The following' table illustrates the two sections of the Eocene : 



DIVISIONS. 



LOCALITIES. 



CHARACTERISTIC FOSSILS. 



Upper 



or 



Newer Eocene. 



Vicksburg, Miss., white limestone 

 of St. Stephens, and of Claiborne, 

 Alabama, and part of that in Charles- 

 ton CO., South Carolina. 



Scutella Lyelli. 



Rogersi. 



Pecten Poulsoni. 

 Nummulites Mantelli. 



Limestone in the vicinity of Tampa 

 Bay, Florida. 



Nummulites Floridina. 

 Cristellaria rotella. 

 Ostrea Georgiana. 







Lower 



or 



Older Eocene. 



Fossilliferous sands of Claiborne, and 

 St. Stephens, Al.; of the Washita 

 river, near Monroe, La.; Pamunkey 

 river at Marlbourne, and Eocene 

 green sand, on James river, below 

 City Point, Va.; Fort Washington, 

 Piscataway and Upper Marlborough, 

 Md. 



Cardita planicosta. 



Blandingi. 



Crassatella alta. 

 Ostrea sellseformis. 

 Turritella Mortoni, &c. 



The upper lim,estone of Shell Bluff on the Savannah river in Georgia, which 

 contains Ostrea Georgiana and Scutella quinguefaria, overlies strata which contain 

 species of organic remains identical with those of the Lower Eocene of Alabama and 

 Virginia, none of which has yet been found associated with the two characteristic 

 fossils above named. Ostrea Georgiana occurs at Jackson, Mississippi, where its 

 position is said to be below the Vicksburg group. It is therefore the line of 

 demarcation between the Upper and Lower Eocene. 



Fossils of the Nerver Eocene of Mississippi. 

 DENTALIUM. 



D. MississiPPiENSis. PI. 11, fig. 1. — Curved, attenuated above, longitudinally striated, the lines alternated 

 in size. Length 2 1-10. Abundant. It differs from D. thalloides, nob., in having more numerous 

 and much less prominent lines. It is very abundant. 



