Four species of Camarotoechia, 2 of Stenocisma and 1 each of Leiorhynchus, Moorefieldella, Shumardella and Torynifer are described from the Mississippian Madison Group. The concept of speciation for stratigraphic utility is briefly contrasted with the biologic approach. Ranges of the fossils are given in an absolute scale. New species are described as follows: Camarotoechia inaequa, C. tidwellae, Moorefieldella davisi, Stenocisma uniplicata and Torynifer montanus.

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