In June, 1901, the writer made a reconnaissance from Kansas into Oklahoma, for the purpose of studying the relations of the limestones of the Carboniferous and Permian of Kansas to the shales and sandstones known as the Red beds. The results of this trip were briefly summarized in the American Journal of Science,† under the title “The Carboniferous and Permian age of the Red beds of eastern Oklahoma from stratigraphic evidence.” As there stated, it was found that the limestones which are conspicuous in the Kansas section thin southward, and gradually disappear, so that south of the Arkansas river in Indian territory and Oklahoma the section consists of shales and sandstones. The transition in the character of the formations is accompanied in the upper part of the section by a change to a maroon or red color. The approximate limit of the red color . . .