564 [Feb. 26. 



taceous formation, and as forming an intervening link between the 

 secondary and tertiary formations ; but after a careful examination 

 of several localities, presently to be described, I found the w^hite 

 limestone to contain exclusively tertiary fossils, without any inter- 

 mixture of species belonging to the true and unquestionable cre- 

 taceous rocks of New Jersey or Alabama. It appeared to me that 

 there was the same chasm between the cretaceous and tertiary 

 rocks in that part of America which I visited, as has been observed 

 in Europe generally, and those organic remains which have been 

 supposed to be common to the two formations in the United States, 

 have been almost all referred by mistake to the older group, in 

 consequence of part of the white limestone of S. Carolina, which 

 is tertiary, having been erroneously referred to the cretaceous 

 epoch. 



The largest number of eocene shells found in a good state of 

 preservation, ai-e those of Claiborne, Alabama, where a large 

 collection was made by Mr. Conrad, and descriptions and figures 

 of them were published in 1832.* At the same period, Mr. Lea, of 

 Philadelphia, received from a friend a fine collection of the same 

 fossils from Alabama, and referred them also to the period of the 

 London clay of England, and calcaire grossier of Paris. In his 

 work intitled " Contributions to Geology," he gave figures and 

 descriptions of more than 200 species, but unfortunately, in con- 

 sequence of these two eminent naturalists having laboured simul- 

 taneously, and independently of each other, almost eveiy shell 

 received a distinct specific name. For a list of synonyms, I may 

 refer the reader to the appendix to Dr. Morton's " Synopsis of 

 Organic Remains of the Cretaceous Group, Philadelphia, 1834," 

 drawn up by Mr. Conrad. 



I shall now oflfer a few observations on several localities of the 

 eocene strata which I visited, beginning with the most northern, 

 in Virginia, and then proceeding southwards to N. and S. Caro- 

 lina and Georgia. 



Virginia. — Below Richmond, near Coggin's Point on the James 

 River, the Ostrea sellceformis occurs in one of the uppermost of the 

 eocene beds ; and this fossil I afterwards found to be widely cha- 

 racteristic of the formation in S. Carolina and Georgia. At the 

 same place, Cardita planicosta, so common in the London clay 

 and Paris basin, is also found. It cannot be distinguished from 

 one of the common varieties of the European shell, and is accom- 

 panied by an oyster very nearly allied to 0. bellovacina. Profes- 

 sors W. B. and H. D. Rogers, have described and figured several of 

 these fossils in the fifth and sixth volumes of the American Phil. 

 Trans, for the years 1835 and 1839. Near Evergreen, on the 

 right bank of the James River, twenty miles below Richmond, I 

 found, in the eocene marl, a large piece of wood in a state of lignite, 

 7 feet long, and about 1 foot broad, bored by teredo. 



* For some account of the Claiborne strata, see Conrad's " Tertiary Fossil 

 Shells" 1842. 



