OF SOUTH CAROLINA. 185 
pensate for difference of cireumstances. An animal that could live through the winter in shallow 
water, on the southern coast, may require a greater depth in a cold, northern climate. 
There is a variety of Ostrea Virginiana that is very common in lagoons and other localities 
along the coast, which is known as the “Raccoon oyster.” The shells are often eight or ten inches 
in length, and sometimes not more than two inches wide. They generally grow in bunches, 
attached to each other, and run up to the very level of high water. The uppermost ones are con- 
sequently out of the water, and exposed all the time, with the exception of a very short space, at 
high water. 'They have but little time to feed, and are, therefore, scarcely edible; but when the 
young ones are scattered abroad they acquire the characteristic form of the species. 
Now in a severe northern winter, oysters exposed for so great a length of time could scarcely 
live; at all events that variety of oyster is not found fossil farther north than North Carolina: and 
a Geologist, aware of the fact, could distinguish, by its presence, a group of North or South Caro- 
lina ‘Tertiary fossils. ‘There are many P. Pliocene beds along the coast, abounding in fossils buried 
in the sand, precisely as they lived. Did we know exactly the habits of their living representa- 
tives it would be easy to determine whether or not any material change of level had taken place in 
these beds, since the shells were thus buried.* 
That beds extending between 7° of Lat. and 6° of Lon. should present considerable diversity 
in their organic remains, was to be expected. A collection of Tertiary fossils from Maryland would 
at once be known, by its containing Fusus parilis, F. rusticus, Corbula idonea, Panopea Ameri- 
cana, and Mactra ponderosa. And a similar collection from Virginia would be characterised by 
such fossils as Cardium Virginianum, Pecten decemnarius, P. Virginianus, Fusus exilis, Venus 
capax, Pectunculus tumulus, and Anomia Ruffini. The North and South Carolina beds are 
readily distinguished by such conspicuous fossils as Pyrula excavata, Cyprea Caroliniana, Conus 
adversarius, Mitra Caroliniana, Chama arcinella, Pecten Mortoni and Arca lienosa. Many of 
the fossils have a wide range, but are restricted in numbers. Venus tridacnoides and Fusus quadri- 
costatus, which occur abundantly in Virginia, are quite rare in South Carolina. The genus Cyprea 
first appears in Virginia, but increases in numbers towards the South, till, in South Carolina, it 
becomes quite common. 
After all, it seems to me that beds having so wide a horizontal range, might differ greatly in the 
relative proportion of recent mollusca embedded in them, and yet be contemporaneous. [ can 
readily conceive how a change might take place on the coast of Massachusetts, at this moment, 
that would affect the mollusea living there, and yet not be felt by those on the coast of South Caro- 
lina—so that when both were converted into dry land, the relative amount of recent species would 
differ widely. 
Post PLIocENrE. 
The Post Pliocene, although wanting the interest always connected with the vast antiquity of 
the older rocks, is nevertheless highly interesting, as the link connecting the past history of the 
earth with the present. We have here, before our eyes, the process in operation by which the bed 
* There are at present some active students of Natural History in South Carolina that will not allow this interesting field to 
remain long unoccupied, 
47 
