160 GEOLOGICAL SURVEY 
it is a perpendicular escarpment, seventy or eighty feet in height, composed of beds of marl, of 
various thickness, and differing much in the amount of carbonate of lime present in them. The 
bluff extends inland some distance, where it is no longer washed by the river. O. Selle@formis 
and O. Georgiana are the most prominent fossils. 
At Griffin’s Landing, a few miles lower down the river, O. Georgiana is found projecting, in 
great numbers, from the horizontal surface of the marl, where it 1s washed by the river—the hinge 
invariably downwards; forcibly reminding one of the beds of the long variety of O. Virginiana, 
found along the shores of Charleston harbor. Had the stratum in which the fossils are embedded, 
been black, instead of white, the resemblance to a recent oyster bed would be complete. 
Fragments of jasper, chalcedony, and agate, scattered over the surface, above the Lower Three 
Runs, give evidence of the existence of the buhr-stone, although I did not find it in place, below 
the bridge on Upper Three Runs, where it shows itself in heavy beds of silicious sandstone, con- 
taining fragments of shells. 
Mr. Ruffin noticed the numerous indications of denudation presented on the western side of the 
District. On the last mentioned stream thick beds of gravel, containing rolled pieces of marl 
stone, occur, similar to those already mentioned, on the Salkehatchie and on Huspa Creek, in Beau- 
fort. The remains of fishes in these beds, prove that they have been accumulated during the 
Tertiary period. 
The section indicated as extending along the Santee from Mazyck’s Ferry to Stout’s Creek, is 
about seventy-five miles in length. It was right to expect much diversity in the fossils distributed 
over so great an extent, and it was curious to observe the different groups as they made their 
appearance, one after the other. 
Of all the Eocene fossils of South Carolina, Gryph@a mutabilis and Cardita planicosta are the 
most persistent, as they extend from the buhr-stone to the upper beds of the Santee, and the former 
is even found on the Ashley. O. Selleformis and O. Panda first appear in the coralline bed at 
Pooshee ; and Nautilus Alabamiensis, in the green sand at Mr. R. Mazyck’s, with Seutella Lyelli, 
Terebratula Harlani; and here, too, the first cetacean is found, which has continued to exist up to 
the time of the deposition of the Ashley. O. Compressirostra is found on the Santee Canal alone. 
Fossits oF THE SANTEE BeEps. 
Cetacea. 
Zeuglodon, 
lower maxilla, teeth and vertebre. 
Sauria. 
Teeth, (undetermined.) 
Fishes. 
Carcharodon, Diodon, 
Lamna, Pyenodus, 
Oxyrhina, Ceelorhyncus, 
Otodus, Pristis. 
