Correlations between the type Permian System of Russia and North American strata have been difficult for decades because of biostratigraphic and nomenclatural confusion. Consequently, a standard Permian section was established in west Texas that is widely accepted throughout North America. Series of the North American standard section are, in ascending order, Wolfcampian, Leonardian, Guadalupian, and Ochoan. This nomenclature was adopted for usage in Kansas in 1951, but was later abandoned in favor of local terminology. However, direct biostratigraphic correlations between Kansas and the west Texas standard section have now been firmly established, and local chronostratigraphic names, i.e., Big Blue, Lyon, Geary, Cimarron, and Custer, have not been widely accepted. The Kansas Geological Survey has now readopted usage of the Wolfcampian Series for rocks of the Admire, Council Grove, and Chase Groups; the Leonardian Series for rocks of the Sumner and Nippewalla Groups; and the Guadalupian Series for rocks of the Whitehorse, Day Creek, and Big Basin Formations. The Wolfcampian Series in Kansas (and elsewhere in North America) contains post-Virgilian (latest Carboniferous) strata that predate the classical Permian System of the Russian type section. Consequently, the Pennsylvanian/Permian boundary will probably have to be raised stratigraphically to conform to global usage.