Mesozoic and Ccenozoic Geolo<jy and Paloeontology. 259 



Cooper river, about seventeen miles from Charleston, South Carolina, 

 Scutella caroUniana, now Mellita carotin iana, and S. macrophora, 

 now Encope macropliora. 



In 1843, i\rr. Conrad* described, from the Miocene at jS'ewbern,North 

 Carolina, Cliffs of Calvert, Maryland, Petersburg, Virginia, and other 

 places, Carditamera carinata^ C. protracta. Area triquetra, JSFiimla 

 liciatxi, Pectunculus parilis, Pecten biformis, P. tricenarius, P. vicen- 

 arius, Tellina laevis, Lucina multistriata, Amphidesma cequatum, 

 CtrissateUa turgidida, Crepidula spinosa, Fidgur rugosus, Buccinum 

 bilex, B. JiUcatum^ B. fossidatum, B. lienosicm, B. praerupturii, B. pro- 

 tractum, B. sexdentatum, CanceUaria corhida, Oliva dnpUcata, Pijra- 

 mideUa arenosa, Fusus migrans, F. devexus, Voluta mutabilis, Ovida 

 iota, llonodonta exoleta, Echinus improcerus, E. philanthropus, 

 Venus cribraria, Plicatida densata, Crepidula densata, Area propa- 

 tida, now Granoarca propatida, a subge»us of Barbatia, A. scalaris, 

 Cyrena densata, 3Iactra triquetra, Venus capax, Artemis elegans, 

 Loripes elevata, Solen directus, S. ensiformis, Turritella bipartita, 

 Sealaria procera, Pleurotoma multisectum, Buccinum harpidoides, 

 Fusus cannabinus, Terebra curvilirata, TurbinoUa pileolus, Spatangus 

 orthonotus, now Amphidetus orthonotus; from the Eocene at Chapel 

 Hill, North Carolina, TeUina arctata; from Pamunkey river, Virginia, 

 Anomia ruffini; and from the Jackson Group, Anomia jugosa. He 

 said, that in a. few hours' examination of the Miocene marl, in the 

 vicinity of Petersburg, Va., he was enabled to collect about 100 distinct 

 species. This localit}^ is the western limit of the Miocene, which is 

 here based on granite, and is the spot, in which, to search for the estu- 

 ary and fresh water shells of the Miocene period. The elevation is 

 considerabh^ more than 100 feet above tide, and as the rise decreases 

 toward the sea, it is probable that the primary rocks continued to 

 be uplifted even after the era of the Miocene; indeed, how can we 

 otherwise account for the elevation of fossiliferous beds, even of those 

 of the Post-pliocene period. 



It is an interesting fact that the Miocene estuaries were inhabited 

 by two species of bivalves, now extinct, of the same two genera which 

 still occur in similar situations in Florida and Alabama, that is at the 

 confluence of rivers and ba3's, where the water is nearly fresh. These 

 genera are Gnathodon and Cyrena, both of the family Cyrenidoe. The 

 extinct Gnathodon has a considerable resemblance to the recent 

 species, but the Cyrena is wideh^ different from the living shell. These 



Proc. Acad. Nat. Sci., vol. i. 



