102 ON THE SECONDARY AND TERTIARY FORMATIONS 



merely indicate relative position, and are therefore sufficient at 

 present ; the latter imply a relative proportion, of course not very 

 exact, of extinct and recent shells ; and though our own forma- 

 tions may now each give about the same proportion with the 

 ]Miglish formations, still when two hours' work may discover more 

 than twenty undescribed species in one locality, besides some 

 recent species not before noticed in the formation ; and when our 

 knowledge of the living shells of our coast is so imperfect, it 

 certainly proves that the adoption of these new names would now 

 be hasty. It would be at once taking it for gi-anted, (as it is 

 certainly not proved,) that our sti'ata will be readily divisible into 

 the same three formations as those of Europe ; and all difficulties, 

 if any are hereafter encountered, will be too apt to be made to 

 bend, or to be neglected, for thp sake of keeping to this favorite 

 but unproved system of classification. This subject, I hope, will 

 be more fully discussed by Mr. Conrad, and sustained by more 

 complete details than I am able to furnish. 



At the locality last mentioned, near the boundary line, are 

 found through the fields singular deposits of oyster shells, each 

 extending over several feet square and about t^vo feet deep. No 

 account is preserved of the time or cause of these collections. 

 They were made centuries ago, probably by the Indians. Corn 

 does not grow well by these heaps, at which I was rather 

 surprised. 



There is a well-known locality of the secondary limestone at 

 the Eutaw Springs, near Nelson's ferry over the Santee, in the 

 western part of Charleston district. The striking similarity of 

 this rock to that in Jones county, North Carolina, first attracted 

 my attention. Like it, the limestone rose above the surface in 

 heavy ragged ledges, here at least fifteen feet high ; it was of the 

 same light yellow color, and contained similar fossil shells. 

 Similar springs too rise among the ledges of the rock, and they 

 contain the same recent shells, and water-cresses in greater abun- 

 dance. But the water, I noticed, was lukewarm, and one of the 

 largest of the streams, after running only about fifty yards, sud- 

 denly disap})earcd under the limestone, and was no more seen. 

 The rock does not contain a great variety of fossil shells : the most 



