The writer has connected outcrops of the Cherokee and Marmaton on a faunal basis, and has projected these Pennsylvanian formational units by means of well samples throughout a very wide area, demonstrating the correlation of beds in Wyoming and Colorado with similar beds in Kansas and Oklahoma.

Some of the formations in Wyoming and western Colorado seem from their outcrops to belong to a province different from that of their equivalents which crop out in Kansas and Oklahoma; however, by means of well samples, the equivalence of these beds may be demonstrated and a mixing of the faunal suites shown, thus eliminating the possibility of different provinces.

The writer discusses the influences and regional conditions surrounding the deposition of the Marmaton and Cherokee.

The McCoy formation is here introduced. A brief faunal paper on the McCoy formation will appear in the Journal of Paleontology,(FOOTNOTE 3) where all the new fossils mentioned in this paper will be described.