This paper gives briefly some of the results of the field work in western Kentucky during the summer of 1929, and more briefly of that during the summer of 1926. The section covered is the extreme western portion of Kentucky, commonly known as the “Jackson Purchase Region.” This region includes eight counties bounded by the Tennessee and Mississippi rivers on the east and west, respectively, by the Ohio River on the north, and by the Tennessee State line on the south. The region is a little more than 2,000 square miles in area, of which the Tertiary comprises approximately 75 per cent. The writer was assisted in the field work by Charles W. Wilson of Princeton University. The collections of Wilcox and Jackson plants have been submitted for determination and description to Prof. E. W. Berry of Johns Hopkins University. Professor Berry has previously described a number of fossil . . .