i¢ | i ae 
OF SOUTH CAROLINA. 177 
Dr. Zimmerman’s marl is similarly situated. The existence of this black and well known sub- 
stance, immediately below the marl of Darlington, is a fact deserving the notice of those in search 
of marl for agricultural purposes, for when it is met with, it is useless to continue the search far- 
ther below. 
Around the village localities are quite numerous. The marl is generally below the surface, being 
covered by superficial beds of sand, clay, and the accumulating organic matter of swamps. They 
are, in all respects, similar, containing nearly the same amount of caleareous matter, and having 
the embedded organic remains identical. 
On the land of G. W. Dargan, Esq. a deposit was discovered, interesting for the remains of the 
Mastodon found in it. Among these were two perfect molars, one of which, through the liberality 
of Mr. Dargan, is now in the College Cabinet, at Columbia. The bed, at this place, occurs in a low 
swamp, covered with three or four feet of black mud—the Mastodon teeth were found immediately 
under this, and enveloped in the marl. The latter is composed of broken and comminuted shells, 
but it is difficult to give a complete list of the fossils found in it. I recognised, however, the fol- 
lowing. 
Fissurella redimicula, Anomia ephippiwm, 
Dentalium dentalis, Lucina divaricata, 
Natica duplicata, Astarte concentrica, 
Conus adversarius, Arca incongrua, 
Pectunculus subovatus, Solen ensis, 
‘ 5-rugatus, Panopeea reflexa, 
Venus tridacnoides, Ostrea disparilis, 
Carditamera arata, “ — Virginiana, 
Cardium laqueatum, Artemis acetabulum. 
At Col. Ervin’s, about a mile distant, a small stream has exposed the eldest and best known Plio- 
cene locality in the State. It is about ten feet thick, composed of fragments of shells and sand. 
The fossils are ina fine state of preservation, and an extensive excavation afforded an excellent 
opportunity of observing its fossil contents. I made a collection here, that aided me very mate- 
rially in settling the true position of this portion of our Tertiary. The number of forms common 
to these beds and the Tertiary of North Carolina, but not found in Virginia, becomes quite striking: 
such, for instance, as Cassis Hodgii, Cerithium Carolinensis, Conus adversarius, Cyprea Caro- 
linensis, Lucina Jamaicensis, Mitra Carolinensis, Mytilus incrassatus, Pectunculus 5-rugatus, 
and many others, which will appear in the appended list. 
Another interesting locality occurs on the land of the Rev. Mr. Campbell,* where, together with 
disconnected valves of Gnathodon and Cyrena, \ found fragments of the horns of a deer. The 
existence of these genera of shells, Gnathodon and Cyrena, that can live only in the brackish 
water of estuaries, indicates the circumstances under which the Darlington beds were deposited. 
There are other interesting localities on Swift Creek, near the village, which are about the north- 
ern limits of this formation. 
*Mr. Campbell has rendered important service to the District, by his numerous discoveries of localities of marl, and I have to 
acknowledge my obligations to him for a fine suit of fossils. 
45 
