I N TEOBUC'TIO N . 

 The species found in South-Carolina are distributed among the following classes: 



Polyparia, - - - 



- 2 



Brachiopoda, - - - 



2 



Eohinodermata, 



- 9 



Lamellibranchiata, 



- 106 



Bryozoa, - - - - 



- 9 



Gasteropoda, - - - 



75 



Total, 



Table showing the geographical distribution of the same : 



203 





Found in the Meio- 

 cene of Virginia, 

 and also in South 

 Carolina. 



Found in the Pli- 

 ocene of N and S. 

 Carolina. 



Found only in the 

 Pleiocene of South- 

 Carolina. 



Known to be in 

 existence. 



Polyparia 



Eohinodermata, . . 

 Bryozoa, .... 

 Brachiopoda, . . . 

 Lamellibranchiata, . 

 Gasteropoda, . . . 



2 



3 



2 



34 



23 



3 



5 



9 



5 



16 

 16 



1 



53 

 31 





64 



8 



46 



85 



The sixty-four species found in the Meiocene of Virginia are rare in the Pleiocene of 

 South-Carolina; of some, only a single individual specimen or valve has yet been discov- 

 ered; for instance, Chama corticosa, and Pecten septemnarius. 



Groups of fossils from Maryland, New Jersey, Virginia, North and South Carolina, 

 could be readily distinguished from each other even by persons not familiar with their 

 specific characteristics; for example, Fusus parilis, F. rusticus, Corbula idonea, Panopea 

 Americana, and Mactra ponderosa, would represent the Meiocene of Maryland; Cardium 

 Virginianum, Pecten decemnarius, P. Virginianus, Colijs exilis, Venus capax, Pec- 

 tunculus tumulus, and Anomia Ruffinii, the Meiocene of Virginia, whilst the Pleiocene 

 of North and South Carolina would be distinguished by such forms as Cypr^ea Caroli- 

 niana, Conus adversarius, Mitra Caroliniana, Pecten Mortoni, Arca lienosa, A. 

 htans, Galeodia Hodgii, Janira hemicyclica, Fasciolaria distans, Busycon Conradii. 



There is also considerable difference in the tithological and minerological character of 

 these formations, the one indurated more or less, and the other comparatively soft and 

 friable. According to Mr. Ruffin, the Meiocene of Virginia does not average forty per 

 cent, of carbonate of lime, whilst in the Pleiocene beds we find about seventy per cent. 



The deposits of the Pleiocene period in South-Carolina are confined to mere patches, 

 occupying the depressions in the Eocene and Cretaceous rocks which have been protected 

 from denudation by the more elevated portions of the beds on which they repose. Rising 

 gently from the Atlantic coast, they reach their greatest elevation in Darlington District, 

 and exposures occur in Sumter, Marion, Horry, Colleton and Charleston Districts. 



