OF SOUTH CAROLINA. 163 
this interesting locality after having observed this, and cannot, therefore, say whether or not these 
nodules had absorbed salt from the spray of the brackish water of the river, or it existed in them, 
as an original constituent of the marl. If they extend into the bluff, beyond the surface, the latter, 
of cowrse, must have been the case. 
Fossils are quite rare in all the lower exposures on the Cooper, and I only identified here Bala- 
nus peregrinus, Pecten calvatus, P. membranosus, and Anomia jugosa, and some teeth of Lamna. 
The bluff at Mepkin is a continuation of this, although some portions are wanting at interme- 
diate points. The upper surface of the marl, on Cooper, is quite undulating : sometimes it rises into 
sections twenty or thirty feet in height, and then sinks to the level of the water, or disappears alto- 
gether. The Mepkin bluff is from ten to fifteen feet above tide, and has the same fossils as the 
section at Strawberry Ferry. Near the mill, the marl is overlaid by a bed of sand and gravel, 
mixed with caleareous pebbles, and containing fragments of bones and teeth of fishes—all trans- 
ported from a distance; and in all respects resembling a bed found on the land of Dr. Barker, near 
Mulberry. Through this latter deposit a ditch has been cut, in which I collected numerous teeth 
of the genera Lamna, Oxyrhina, and Otodus. 
On the opposite side of the river from Mepkin, the marl is found very near the surface, over a 
wide extent. At Point Comfort some excavations have been made, in a rich white marl; and on the 
plantation of Col. Ferguson, a long canal has been excavated in the same bed. Still farther from 
the river, near Monk’s Corner, it is again exposed, somewhat altered in its appearance and mineral 
character. On the road a bed appears, which has lost the granular structure characteristic of the 
marls of this region. It resembles a white calcareous mud, such as would be deposited in the still 
waters of a lagoon. A bed very similar to this occurs on the plantation of Dr. Barker; and these 
are the only deposits in which I have observed any thing like stratification: every where else the 
entire substance of the beds appears to have once existed in the form of an immense pulpy, calea- 
reous mass, and then to have assumed its present granular structure, by concretion. Even the few 
fossils embedded in it are not disposed in layers, that would indicate what was formerly the surface, 
but are scattered throughout the mass. 
On the Santee, on the contrary, where the maz! itself is not stratified, there is frequently a bed 
of oyster shells, or a fossilliferous stratum of some sort, to enable us to determine the mode of 
deposition. 
It was stated that the Santee beds, at least in the form of bluffs, are principally confined to the 
left bank of the river: on the Cooper they are pretty equally distributed. While Mepkin is on the 
left, Mulberry and Steep Bluff are both on the right. The latter presents a fine section, extending 
from the river a considerable distance. I found here Pecten calvatus, P. membranosus, Scutella 
crustuloides, Conus gyratus, and one or two species of coral. 
On my way up the river I saw a canal cut in the marl, and at Lewisfield the same portion 
of the formation is finely exposed, frequently without any superincumbent beds of sand or loam. 
From this point upwards fossils become more abundant, and Gryphea mutabilis makes its appear- 
ance in great numbers at Mr. Mayzick’s, on a bald hill side; a very fine Scalaria also oceurs at 
this interesting locality. 
Steep Bluff, a little higher up, is another noted section. It is at the southern extremity of the 
