Fourteen taxa are described from Hemingfordian (early Miocene) to Hemphillian (early Pliocene) deposits of western North America and Florida. New taxa includeEdaphocyon lautus, new species;Arctonasua floridana, new genus and species;Arctonasua gracilis, new species;Arctonasua minima, new species;Arctonasua eurybates, new species;Arctonasua fricki, new species;Lichnocyonphoenicus, new genus and species; andParanasua biradica, new genus and species. The earliest known occurrences (Hemphillian) ofNasuaandProcyonare documented. Cladistic analysis demonstrates thatParanasuais the primitive sister taxon ofProcyonandNasua; thatArctonasuais probably most closely related to the late TertiaryCyonasuagroup of South American procyonines; and that the primitive sister group of the Procyoninae discussed in this paper includesBassariscusand the European Agenian and Orleanian (early Miocene) genusBroiliana.