Mesozoic and Ccenozoic Geology and Paleontology. 253 



T. A. Conrad* described, from the Miocene, at Yorktown, and other 

 places in Virginia, Mactra confraga, 31. cofigesfa, 31. modicella, 3f. 

 clathrodonta, now Bangia clathrodonta, Chama congregata, C. 

 corticosa, Petricola centenaria, Pectea eboreas, Cytherea marylandica, 

 F^dgur mGilis; and from Choplank river, near Easton, Mar3dand, 

 Corbula idonea; from the Eocene, at Claiborne, Alabama, Corhula 

 oniscus, Venerupls subvexa, Cardita alticosta^ Astarte tellinoides, A. 

 unguUna, Pectunculns stamineus, P. cuneus, now Limopsis cuneus, P. 

 trigonellus, Lucina dolabra, L. panda fa, Nucula bella, JST. caelata, 

 Melongena alveata, now Cassidulus alveatus, Crepidula Ih^ata, Solar- 

 ium elaboratum, now Architectonic a elaborata, Sigaretus bilix, and 

 Typhis gracilis. 



In 1834, Mr. T. A. Conradf identified the Eocene at Claiborne, Ala. ; 

 at Eutaw Springs and Nelson's Ferry, on the Santee river; at Shell 

 Bluff, near Milledgeville, in Georgia; at Shell Bluff, on the Savannah 

 river, fifteen miles below Augusta; at Fort Gaines, on the Chattahoo- 

 chee, and other places; from all which he projected the continuity of 

 the strata, commencing in Maryland, at Fort Washington, and extend- 

 ing in a southerly direction across Virginia, North and South Carolina, 

 and westerly across Georgia, Alabama and Mississippi. His diagram, 

 representing the strata composing the bluff at Claiborne, showed, in 

 descending order: 1. Diluvium, 20 feet; J. Whitish, friable limestone, 

 45 feet, containing Sciitella lyelli ; 3. Six feet indurated limestone, 

 where the fossils occur in casts; 4. Ferruginous, siliceous sand, 14 

 feet, containing Cardita planicosta, Goi^bis lamellosa, and Pyramidella 

 terebellata ; 5. Sand, with a calcareous cement, 3 feet, containing Os- 

 trea sellaeformis ; 6. Soft, lead-colored limestone, 70 feet, containing 

 0. sellaeformis in abundance, and rarely Plagiostoma dumosum; 7. 

 Friable, lead-colored limestone, of unknown thickness, containing Car- 

 dita planicosta, a shell very characteristic of the Eocene. He remarked 

 that the Plagiostoma dumosum, passed from the cretaceous rocks to 

 the Eocene; that the Eocene at Claiborne appeared to be older than 

 the Eocene of Europe, and older than the deposit at Fort Washing, 

 ton, Md. 



He described, from the Eocene of the Southern States, Tellina scan- 

 dula, Pectunculus perplanus, now Limopsis pe7ylana, Fusus irrasus, 

 F. raphanoides, F. salebrosus, F. sexangulatus, F. symmetricus, Cassis 

 brevicostatus, C. tcciti, Cerithium nassula, C. solitarium, Ancillaria 



* Am. Jour. Sci. and Arts., vol. xxiii. 

 f Jour. Acad. Nat. Sci., vol. vii., part 1. 



