D. W. Zangdon, Jr. — Some Florida Miocene. 323 



Lucina contracla Say. ( Chama congregata) 



Lucina crenulata Con. 



Lucina cribraria Say. 



Lucina sp. f 



Grassatella Marylandica Con. 



Venus concentrica Gmelin. 



Venus cancettata Lin. 



Dione cribraria Con. 



Mercenaria Rileyi Con. 



Circe metastriata Con. 



Cardita granulata 



Mactra similis Say. 



Nucula ( Yoldia) acuta Con. 



Nucula dallabella H. C. Lea. 



Nucula hmatula Say. 



Corbula cuneata ? Say. 



Ensis ensiformis Lin. 



Pecten eboreus Con. 



Tellina, 2 sp. ? 



Jrca incongrua Say. 



,4rca lienosa Say. 



Pectuncul.us subovatus Con. 



Ostrea disparilis Con. 



Panopea reflexa 



Carcharodon megalodon Ag. (tooth). 



Balanus sp. 



Stratum 5, from which only a few of the species were col- 

 lected, contains among other fossils : 



Marginella Hmatula Con. 

 Solarium perspectivum Lin. 



Cytherea reposta Con. 

 Mercenaria tridachnoides Lam. 

 Cardita arata Con. 

 Cardium muricatum Lin. 



Cer ithium sp. f 

 Strombus sp. ? 



Hemicardium hemicardium Lin. 

 Lucina Pennsylvania Lin. 

 Lucina divaricata Lam. 

 * Tellina alternata . 



A comparison of the foregoing list with Meek's Check Listf 

 and the valuable compilation of Prof. Heilprin^: shows that of 

 the 63 species enumerated above, 44 or 70 per cent are found 

 in South Carolina ; 40 or 64 per cent are found in North Caro- 

 lina ; 26 or 41 per cent in Virginia ; and 24 or 38 per cent 

 among the newer beds in Maryland. A very fair inference 

 then is that these Alum Bluff deposits are members of Dana's 

 Sumpter Epoch or Heilprin's Carolinian, only one of the species 

 enumerated, Crucibulum ramosurn Con., being found in Heil- 

 prin's Marylandian, though a closer study of the fossils made 

 possible by further collections may point to a faunal relation- 

 ship to an older epoch. 



These Miocene strata dip toward the south about twenty-five 

 feet to the mile, and are soon covered by the sands of the Drift 

 and the cypress swamps so common along this coast. 



Immediately underlying these Miocene sands is a limestone 

 of uncertain age, but which the writer is inclined to class with 

 the Miocene beds. 



Southward from .Rock Island, nine miles by water, above 

 Chattahoochee or River Junction, Florida, the white orbitoidal 

 limestone disappears, and in lieu thereof there is a rock more 

 argillaceous and siliceous in character resembling some phases 

 of the Eocene Buhrstone. This limestone is very well devel- 

 oped in a railroad cut about half a mile east of the Chatta- 



* The above determinations were made by aDd with the assistance of Mr. Tru- 

 man H. Aldrich, of Blocton, Ala. 



\ Smithsonian Miscell. Col., vol. vii. 1867. 



X U. S. Tertiary Geology, Angelo Heilprin, 1884. 



