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 as 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 Platanus, Acer, Ulmus, Alnus, Populus, Betula, Smilax, d&c., 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 ean be made with sections of the 
other two deposits. 
* Remarks, &c., by F. B. Meek and F. V. Hayden. Proceedings of Academy of Natural Sciences, Philadel- 
phia, June, 1856. 
