568 BERRY: MESOZOIC FLORA OF ATLANTIC COASTAL PLAIN 
of these beds with the Neocomian of the Old World positive evi- 
dence is lacking that a part may not be older than Cretaceous. 
Subsequently, Professor Hilgard (Geol. and Agr. Miss. 61. 1860) 
described the beds in Mississippi beneath his Tombigbee sands 
as the Eutaw group and referred them to the Cretaceous. The 
following year Meek and Hayden restated their views and defi- 
nitely correlated the beds in Alabama with the Dakota of the 
Western Interior (Proc. Acad. Nat. Sci. Phila. 13: 419-421. 
1861). 
Again in 1876 Meek (U. S. Geol. Surv. Terr. 9: 38-42) re- 
affirms his belief that the basal Cretaceous of Alabama is of the 
same age as the plastic clays of New Jersey and the Dakota 
sandstone of the Upper Missouri section. 
All of these geologists failed to discriminate the Tuscaloosa 
from the overlying sands and laminated clays of what is now 
known as the Eutaw formation. The first reasonably complete 
account of the Tuscaloosa formation is given by Smith and Johnson 
in the publication previously alluded to. From the attitude, 
lithologic ch ter, and stratigraphic position of the beds they cor- 
related the Tuscaloosa with the Potomac of the Middle Atlantic 
slope, which had just been named and briefly described by McGee 
(Rep. Health Officer Dist. of Columbia for the year ending June 
30, 1885: 19-21, 23-35), a natural correlation since the Potomac 
as understood in the earlier days of its study included beds which 
according to the opinions of different students were referred to 
various levels ranging from the Triassic to the Cretaceous and 
which subsequent study has shown to constitute a series of well- 
marked formations, the oldest of Neocomian age and the youngest 
of Cenomanian age. 
From the year 1883 down to the present Dr. Eugene A. Smith, 
the distinguished state geologist of Alabama, has added to our 
knowledge of these deposits, being assisted in the earlier years 
by L. C. Johnson and D. W. Langdon, Jr. The discovery of all 
of the noteworthy localities for fossil plants is due to their efforts. 
In 1884 some leaf impressions collected by Langdon in Bibb 
County were submitted to Leo Lesquereux, among which he 
recognized a species of Podozamites which he thought might 
indicate a pre-Cretaceous age. Lesquereux afterward determined 
