741 
In conclusion, Mr. Lyell offers the following general observations. 
The part of South Carolina and Georgia which lies between the moun- 
tains and the Atlantic, and of which he examined a portion near the 
Santee and Savannah rivers, has a foundation of cretaceous rocks con- 
taining Belemnites, Exogyre, &c., overlaid first by the eocene lime- 
stone and marls, and secondly by the burr-stone formation with the 
associated red loam, mottled clay, and yellow sand. According to 
Mr. Vanuxem’s observations, a tertiary lignite deposit sometimes in- 
tervenes between the cretaceous and eocene series. The remarkable 
difference in the fossils of the eocene strata at different points, as 
the Grove on Cooper river, the Santee canal, Vance’s Ferry, Shell 
Bluff, Jacksonborough, and Wilmington, might lead, Mr. Lyell states, 
to the suspicion of a considerable succession of minor divisions of the 
eocene period. That the whole are not precisely of the same age he 
is willing to believe, but he is inclined to ascribe the difference prin- 
cipally to two causes: Ist, that the number procured at each place 
is small and therefore represents only a fractional porsion of the en- 
tire fauna of the period, so that variations in each locality may have 
arisen from original geographical circumstances ; and 2ndly, no great 
eocene collection has been made from any part of the United States. 
Some of the burr-stone fossils occur in the limestone, and Mr. Lyell 
thinks the former may hear to the latter a relation analogous to that 
which the upper marine sands of the Paris basin bear to the calcaire 
grossier. 
With respect to the conclusion stated in the beginning of the pa- 
per, that he had been unable to find any beds containing an inter- 
mixture of cretaceous and tertiary fossils, Mr. Lyell says, it would 
require far more extended investigations to enable a veologist to de- 
clare whether there exist in the Southern states any beds of passage, 
but he affirms that the facts at present ascertained wiil not bear out 
such a conclusion. 
The generic affinity of the cretaceous fossils of the United States 
to those of Europe is stated to be most striking, and Mr. Lyell ob- 
served in Mr. Conrad’s collection from Alabama a large Hippurite, 
a point of analogy not previously recorded. 
The proportion of recent shells in the eocene strata of the United 
States appears to be as minute as in Europe, and the distinctness of 
the eocene and miocene testacea hitherto observed to be as great. 
Mr. Lyell says, it is also worthy of remark, that the recent shells found 
in the American miocene beds are not only in the same proportion to 
the extinct as those of the Suffolk crag, or the Faluns of Touraine, 
but that they also agree specifically in most cases with mollusea in- 
habiting the neighbouring sea; in the same manner as the recent 
miocene species of Touraine agree for the greater part with species 
now living on the western coast of France or in the Mediterranean, 
and as the recent testacea of the crag are identifiable with species 
belonging to the British seas. This result appears to Mr. Lyell to 
confirm the accuracy of conchological determinations ; for if, on the 
contrary, it should be maintained, that the number of recent species 
is so enormous, and different species resemble each other so closely as 
