108 Tertiary Strata of the Atlantic Coast. 
worn, and may have been washed out of distant localities of the me- 
dial Pliocene. At all events, the mass of fossils consists of the most 
common shells of the middle and southern states, and have so recent 
an aspect, that most geologists would compare them with those of 
Italy, which Mr. Lyell cites as examples of his newer Pliocene. 
In these interesting beds, occur two fresh water shells, Rangza cy- 
renoides, Des Moulins, and Cyrena carolinensis,* which proves that 
an estuary, in which the waters were nearly or quite fresh, existed 
m such proximity to the beds of marine shells, that its products have 
been transported by currents into the sea, in proof of which | may 
observe that the fresh water genera are invariably much water worn. 
The contiguity of the land or shore of the Phocene ocean is strong- 
ly marked by the remains of quadrupeds, which have been dug out 
of the “ marl pits,” in company with the marine testacea, and if 1 
have been correctly informed, in some instances, encrusted by Ba- 
lani and other sessile shells. Among these exuviae, the horns of a 
deer, and teeth of the mastodon, are conspicuous, and although it 
may be objected that such remains, like bowlders, may have been 
transported from a great distance, by violent currents, yet the fact of 
shells having attached themselves to the bones, and the entire ab- 
sence of all quadruped remains in other marine deposits, lead to the 
supposition that they have been washed down the ancient channel 
of the Neuse, and that the shells must have existed either cotempo- 
raneously with the mastodon, or after it became extinct. Mr. Lyell 
informs us of the occurrence of a bone breccia in Sicily, which he 
believes to be of more recent origin than the newer Pliocene. ‘The 
occurrence, therefore, of facts proving the existence of the mastodon 
before or at the same time with the shells of the newer Pliocene era, 
will throw new light on the history of the latest formed Tertiary 
strata. 
It is only in the newer Pliocene that we meet with such evidence 
of the proximity of the ancient coast to the fossil localities, or that 
we find any shells of fresh water origin or even any very decided 
proof of bays and estuaries. It is probable that several localities of 
the medial Pliocene, were formed in situations similar to the har- 
* It is worthy of remark, that these shells are the only bivalves living in Mobile 
bay, near Mobile, where the water is potable, and that although the Cyrena occurs 
in the waters of South Carolina, the Rangia has not yet been observed living in any 
situation north of estuaries of the Gulf of Mexico. 
