156 GEOLOGICAL SURVEY 
settlers. Inland this plain is broken down, and a swamp occurs, along the margin of which a 
white pulverulent marl is found outcropping, as may be seen at Col. Palmer’s. 
On the opposite side of the river, on Dr. Gourdin’s land, the compact, white bed is found, alterna- 
ting with soft beds of marl. The fossils at this locality are chiefly in the state of casts, and 
among them I was able to identify a large, undescribed area, which I found at Wilmington, on 
another occasion. 
A few miles from this, and on the way to Georgetown, marl is again exposed to view. It was 
soft, and had been used on the land to some extent. The most prominent fossil at this locality is 
Graphea mutabilis, which has attained a greater size here than elsewhere in the State. 
Returning to the right bank of the river, the soft marl may be examined to advantage, on the 
plantation of Dr. J.S. Palmer. Above this, the immediate margin of the river is occupied by 
swamps, and of course these beds are no longer exposed—having been removed, by denudation, at 
least as low as the bottom of the swamps. 
To continue the examination of the Santee beds, which I consider the lowest of the calcareous 
portion of the Eocene, we must now turn west, to where they are again laid bare by the head 
waters of Cooper. At Mr. R. Mazyck’s the green sand is visible. We are indebted to Mr. Ruffin 
for a knowledge of this interesting locality, and for having first pointed out its Hocene character. 
He found Gryphea mutabilis, which is very abundant, and Scutella crustuloides. On my first 
visit to this place I added to these Terebratula Harlani, Var. B. well characterised ; Scutella Lyellt, 
Pecten perplanus, and casts of Cardita planicosta, and Plagiostoma gregale. The green sand 
stratum is about four feet thick, much indurated towards the lower part, where fossil shells are 
most abundant. It was during the excavation of this bed, for agricultural purposes, that Mr. Ma- 
zyck discovered the jaw and teeth of Zeuglodon, accurate and beautiful figures of which have 
been published by Dr. R. W. Gibbes, of Columbia. ; 
These remains were accompanied by Lima concentrica and casts of Nautilis Alabamiensis, and 
a very perfect portion of the jaw of Celorynchus,* now in the cabinet of Dr. Ravenel, of Charleston. 
Below this remarkable deposit is a stratum of white marl, abounding in corals, which may be 
designated the coralline bed of the Charleston Basin. From the nature of the surface, it does not 
appear, at this place, in natural sections, but it has been explored, for agricultural purposes, suffi- 
ciently to afford opportunities for examination. 
At Dr. Cain’s 1 found O. Panda and other Eocene fossils; and the Doctor very liberally pre- 
sented me with a perfect tooth of Zeuglodon, from this marl. So that this is the lowest stratum in 
S. Carolina in which the remams of that extraordinary animal are found. 
The excavations at Pooshee, and the rare chance of a field covered with marl, afforded a good 
opportunity of studying this bed. Assisted by Mr. Henry Ravenel, I made a very interesting col- 
lection at this locality, among which were Nautilus auriculata, T., O. Panda, O. Selleformis, and 
an Ostrea, resembling the genus Malleus; three species of terebratula; Plagiostoma gregale ; 
Echinus infulatus, and numerous species of coral. 
At Deveaux’s old mill we found Cardita planicosta and O. Selleformis. 
* This fossil, so much hike Belemnites, was first found by Mr. Ruffin, many years since, in the Eocene of James River. It has 
puzzled every one who has seen it, until I had the pleasure of learning, from Prof. Agassiz, its true affinities. Cclorynchus rectus, 
Ag. appears among the fishes of the London clay. 
