786 
Among these Testacea are several species of Astarte, some very analo- 
gous to those of Suffolk, the Voluta mutabilis, which resembles the 
V. Lamberti, also Conus diluvianus, Lucina squamosa, and L. divari- 
cata. Mr. Lyell says there are many other analogies among the 
Mollusca, besides the occurrence of several corals, Echinodermata, 
fishes’ teeth and bones of Cetacea ; but he shows that the most im- 
portant point of comparison is in the proportion of recent to extinct 
Testacea. Out of eizhty-two species which he collected at Williams- 
burg, sixteen are considered by Mr. Conrad to be recent, and found 
for the greater part living on the coasts of the United States. The 
existing species, therefore, are in the proportion of one-fifth of the 
whole, which agrees well, says the author, with the average per-centage 
in the shells obtained by him in 1840 from the Faluns of Touraine. The. 
entire number of American miocene shells known to Mr. Conrad is 
238, of which thirty-eight have been identified with recent species. 
North Carolina.— In the neighbourhood of South Washington, on 
the north-east branch of Cape Fear river, Mr. Lyell found the dark, 
-bluish marls of the cretaceous series, to which his attention had been 
directed by Mr. Hodge’s paper -in Silliman’s Journal*, They closely 
resemble, in composition and organic contents, those in New Jersey, 
and abound with Belemnites mucronatus, Exogyra costata, and a spe- 
cies of Gryphea resembling G. columba ; Mr. Lyell also found in 
them Oslrea vesicularis and O. pusilla of Nillson, likewise 4nomia 
tellinoides, a species of Plagiostoma, and several new shells. These 
marls extend to the south of Lewis Creek, for several miles along the 
banks of the north-east branch of Cape Fear river, nearly to Rocky 
Point, where they are covered by the Wilmington limestone and 
conglomerate. This formation, which is overlaid by miocene strata, 
and ranges to Wilmington, as well as along the coast to Cape 
Fear river, has been considered by Mr. Hodge, and other geolo- 
gists, to be an upper secondary deposit, or interposed between the 
eocene and cretaceous series; but Mr. Lyell could find in it no or- 
ganic forms which supported this opinion, nor could he learn that any 
had been discovered. Qn the contrary, the only determinable species 
apparently agree with the Lucina pendata, an Alabama shell, and 
Pecten membranosus, both eocene fossils. The organic remains at 
Wilmington are only casts, but are referable to the genera Cardium, 
Nucula, Corbula, Cardita, Venus, Arca, Natica, Oliva, Cyprea, 
Conus, Calyptrea, and Siliquaria. Associated with these remains 
of Testacea are a species of Lunulites and several other corals, the 
claws of Crustacea, and teeth of the Lamna family. Many of these 
fossils occur at Rocky Point, including Pecten membranosus, with a 
Lunulite and a Vermetus subsequently found by the author in the~ 
limestone of the Santee canal in South Carolina. 
South Carolina and Georgia.—Charleston stands on a yellow sand, 
beneath which is a blue clay containing the remains of Testacea that 
inhabit the adjacent seas; and Dr. Ravenel informed Mr. Lyell 
that he had found in it the Gnathodon cyrenoides, not now known to 
occur in a living state nearer than the Gulf of Mexico. The author 
* Vol. xii. p. 632, 1841. 
