548 Geological Society: Anniversary Address, 1843. 
determinable species being of the Eocene age. Again, in South 
Carolina, on the Santee river, a white limestone occurs, which litho- 
logically so resembles one of the upper members of the cretaceous 
deposits of New Jersey, that even Mr. Lyell, at a first view, had no 
doubt it was a portion of the same formation: on examination, 
however, of the fossils, it proved also to belong to the tertiary series. 
This lithological resemblance had erroneously led to the admission 
of several well-known tertiary fossils into the Cretaceous system of 
America, an error which Mr. Lyell has removed. ‘This correcticn 
is valuable, and, though it tends to negative a hope which I 
once entertained, founded upon what my friend Professor Sedgwick 
and myself believed to be very good evidence on the flanks of the 
Austrian Alps, that beds of passage would be discovered between the 
Cretaceous and Eocene epochs, I am bound to say that the transat- 
lantic researches of Mr. Lyell go far towards the establishment of 
an extensive, though I still incline to consider not a general break 
between those periods; for he prudently admits, that evidences dif- 
fering from those he obtained, may be found in the Southern states 
bordering the Atlantic, of which he explored but asmall part. Re- 
ferring you to the abstracts of his memoirs, and knowing that you 
willsoon have from him more complete details, I will not occupy your 
time in attempting to give what would convey an imperfect idea of 
the succession of the widely spread tertiary deposits, which occupy 
nearly all the portion of Georgia and South Carolina between the 
mountains and the Atlantic. Illustrating the observation of Mr. 
Maclure, that the first falls of the Savannah and other rivers of this 
region are at the junction of the tertiary strata with granitic and 
hypogene rocks, Mr. Lyell shows, that at some points, as near Au- 
gusta in Georgia, where the former have been made up of the de- 
tritus of the primary rock, they have the aspect of gneiss; a fact 
quite analogous to that which I had the pleasure of observing in his 
company many years ago in Central France, where the oldest ter- 
tiary and freshwater beds repose at once upon the granites of the 
Puy en Velay. After a laborious comparison of a profusion of fos- 
sil shells from the American strata, in the determination of which he 
acknowledgés the liberal assistance and co-operation of Mr. Con- 
rad, Mr. Lyell sees fresh and strong grounds for adhering to his 
former views respecting the value of testing the age of tertiary 
strata, by the smaller or greater per-centage of existing species 
which are to be detected in each deposit ; for he finds the same pro- 
portions which had been established between the fossils of European 
basins and the living mollusea of adjacent bays, to hold good in the 
Eocene and Miocene deposits of the United States, when compared 
with the existing fauna on their shores. 
In supplying us with new evidences of the recession of the Falls 
of Niagara, which he described last year, Mr. Lyell has also given 
us a sketch of the ridges, elevated beaches, inland cliffs and boulder 
formations of the Canadian lakes and valley of St. Lawrence. After 
referring to the researches of Capt. Bayfield at and around Montreal 
and Quebec, he enters upon a general survey of the great boulder 
