134 
GEOLOGICAL SKETCH OF THE ESTUARY AND FRESH WATER DEPOSIT 
these species are now found inhabiting the streams of Southern Africa, Asia, China and 
Siam; apparently indicating the existence of a tropical climate in these latitudes at as 
late a period a,s the tertiary epoch.”* The flora is also of quite a modern type, many of 
the leaves very strongly resembling those of our existing forest trees, and seem to belong to 
the genera Platcinus, Acer , Uhmis, Alnus , Populus, Betula , Smilax, Ac., and to be of a sub¬ 
tropical character. The following section of the strata, as revealed by the channel of the 
Missouri at Red Spring, near Fort Clarke, will show quite clearly the lithological charac¬ 
ters of the beds of the Lignite Basin, and comparisons can be made with sections of the 
other two deposits. 
* Remarks, &c., by F. B. Meek and F. Y. Hayden. Proceedings of Academy of Natural Sciences, Philadel¬ 
phia, June, 1856. 
