OF SOUTH CAROLINA. 175 
The proportion of recent and extinct species stands thus— 
Gasteropoda . . . . 19 species— 8 recent, or 42 per cent. 
Lamellebra....28 “ —13 & Uo 
GTlotalllerey2 Ps. ies % AT Pl Sy AS Sisto “6 
From Conwayboro’ to Galovant’s Ferry, on Little Peedee, the country is a low, unbroken plain, 
occasionally relieved by a series of undulating sand-hills. The surface is covered with tufts of a 
species of Aristida, that furnishes a poor, harsh food for cattle, and, excepting on the sand-hills, 
where some oaks grow, the trees are magnificent long-leaved pines. Although I saw many lime- 
sinks, there are no natural sections, where observations may be made below the surface. On the 
right bank of the river, above the ferry, the surface is more broken, and the superincumbent beds 
are, in places, washed away. 
About two or three miles from the ferry, and on the land of Mr. H. H. Harrelson, I found a bed 
of marl exposed, on a little stream, not far from the Marion road. It is about six feet in thickness, 
and is laid bare for a distance of one hundred yards. I found init Pecten eboreus, O. Virginiana, 
and O.disparilis. There are other exposures not far distant, and I heard of localities in the neigh- 
borhood where this bed occurs, so near the surface as to be brought to light by fallen trees. Not- 
withstanding a diligent search made along Cat Fish Swamp and other parts of the District, this is 
the only point at which I found any Tertiary beds. 
The black shale of the Cretaceous beds occurs in several places, along the road. I made a similar 
search, with the same result, in Marlboro, both on the Peedee and the Three Creeks. At the latter 
place I found the shale below the surface about fifteen feet. 
The next locality to be examined is found on Giles’s Bluff, on the land of Henry Davis, Esq. 
I have, in another place, mentioned that the Pliocene of this locality is underlaid by the Creta- 
ceous beds, which rise above the river to the height of twenty feet. The Pliocene marl is from 
eight to ten feet thick; the lower part is soft and of a light ash color, and contains fine specimens 
of Pecten Mortoni. This is overlaid by a bed of coarser structure, and of a more ferruginous color, 
and made up principally of calcareous casts of shells, among which Chama congregata is promi- 
nent. Casts of Panopea reflera are also found, in their usual natural position. 
The lower and softer marl is frequently washed away, leaving the upper bed overhanging. A 
little below the principal bluff, the indurated bed is composed altogether of Pectens, lying together 
in every possible position, and often placed one within the other; yet many of the valves remain in 
juxtaposition. 
Another locality, some distance from the river, is composed, in like manner, of Pectens, firmly 
cemented together. Dr, Harllee kindly presented me, from this locality, with the only specimen 
that I had seen in the State, of Pecten septemnarius. Mr. Ruffin also found here a Pecten, which, 
in his Report, is called P. Peedeensis. 
Towards Godfrey’s Ferry the bluff recedes from the river, or rather the river has encroached on 
the opposite bank, leaving the bluff with a narrow strip of low ground between it and the water. 
The upper bed is, here, pretty thick, and is perforated by openings, through which the surface 
water, from some distant point, finds a passage. This bed is seen again at Godfrey’s Ferry, which 
is its southern limit on the Peedee. 
