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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 cori'ection 

 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 a small part. Re- 

 ferring you to the abstracts of his memoirs, and knowing that you 

 will soon have from him more complete details, I Avill not occupy your 

 time in attempting to give Avhat 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 Avith 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, Avhere the oldest ter- 

 tiary and freshwater beds repose at once upon the granites of the 

 Puy en Vclay. After a laborious comparison of a profusion of fos- 

 sil shells from the American strata, in the determination of which he 

 acknowledges 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 pei'-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 mollusca 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 Quebep, he enters upon a general survey of the great boulder 



