422 Proceedings of the Geological Society. 



as yet been impossible to ascertain, no survey having been made. 

 They must however be numerous, for I saw several separated by 

 a slight thickness of intervening strata at points between eleven and 

 twenty miles north-east of Tuscaloosa ; and I am informed, that 

 in one place in the bed and banks of the Warrior River three seams 

 are exposed to view, one above the other, the lowest and largest 

 being ten feet in thickness. 



The more eastern coal-field, or that of the Cahawba, is nearly of 

 equal length and breadth, terminating southwards at Centreville, 

 where it meets the lower cretaceous beds, and extending from thence 

 through Bibb, Shelby, Jefferson and St. Clair counties, to the source 

 of the Cahawba River. In this also numerous beds of coal of good 

 quality have been found, and worked to slight depths. 



A third coal-field on the northern confines of the State of Alabama, 

 is that of the Tennessee Valley. It is separated from the two 

 former by a broad but low chain of mountains, running nearly east 

 and west, which intervenes between the Tennessee and the sources of 

 the Warrior and Cahawba rivers. These mountains, according to 

 Professor Brumby, consist of strata older than the productive coal- 

 measures, and similar to those seen by me in Rook's Valley. 



The coal on the Tennessee, above alluded to, may perhaps be con- 

 tinuous with that of the great Appalachian coal-field. I hope here- 

 after to be enabled to give a more full account of the fossil plants of 

 these Alabama coal-fields, a comparison of which, since they form 

 the extreme southern limit of the carboniferous flora, with those 

 of the north, will deserve particular attention. 



London, June 23, 1846. — The above observations were written at 

 Tuscaloosa in February last, and sent from thence to the Geological 

 Society. On my return to England I found the paper already in 

 type, and about to be printed off, but an opportunity having been 

 offered me of adding this note, I submitted the specimens to my 

 friend Mr. Charles J. F. Bunbury, F.G.S., who immediately com- 

 pared them with published plates and the fossil plants in the Society's 

 collection. The result of his examination confirms the conclusions 

 to which I had arrived, and his specific identification of several of 

 the iVlabama remains with well-known European fossils is highly 



