Mesozoic and Ccenozoic Geoloyy and Palaeontology. 155 



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

 places in Virginia, Mactra confraga, M. congesta, 31. modicella, M. 

 clathrodonta, now Rangia clathrodonta, Chama congregata, C. 

 corticosa, Petricola centenaria, Peoteri eboreiis, Cytherea marylandica, 

 JFulgur incilis; and from Choplank river, near Easton, Marjdand, 

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

 oniscus, Venerupis subvexa, Cardita alticosta, Astarte tellinoides, A. 

 ungidina, Pectuncuhis stamineus, P. cioieus, now Limoitsis cuneus, P. 

 trigonellns, Lucina dolabra, L. pandata, JSTucula bella, iV. caelata, 

 Melongena alveata, now Gassidulus alveatus, Crepidula lirata. Solar- 

 ium elaboratum, now Arcliitectonica elaborata., Sigaretus bilix, and 

 Typhis gracilis. 



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

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

 BlnfF, 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 Maiyland, at Fort Washington, and extend- 

 ing in a southerh' 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 ScitteUa lyelli ; 3. Six feet indurated limestone, 

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

 feet, containing Cardita planicosta, Gorbis lamellosa, and Pyramidella 

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

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

 O. sellaeformis in abundance, and rarely Plagiostoma dumostim; 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, Pectuncidus perplamcs, now Limopsis perpkma, Fusus irrasiis, 

 F. rapJianoides, F. salebrosus, F. sexangulatus, F. symmetricus, Cassis 

 brevicostatus^ C. taiti, Cerithium nassula, C. soHtarium, Ancillaria 



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

 f Jour. Acad. Nat. Sci., vol. vii., parti. 



