LATE MISSISSIPPIAN PRODUCTOID BRACHIOPODS INFLATIA, KEOKUKIA, AND ADAIRIA, OZARK REGION OF OKLAHOMA AND ARKANSAS

Specimens of the Late Mississippian productoid genera Inflatia and Keo kukia from northeastern Oklahoma and northwestern Arkansas, collected from the Boone and ''Moorefield'' Formations, Hindsville Limestone, an d Fayetteville Shale, display morphologic similarities and differences that delineate species and determine their biostratigraphic ranges. G eneric assignments are based primarily on internal characters. Systema tic descriptions include seven species of lnflatia Muir-Wood and Coope r: Productus inflatus McChesney (the type species), P. cherokeensis Dr ake, P. clydensis Girty (figured herein for the first time and for whi ch a lectotype is designated), four new species of Inflatia (I. cooper i, I. gracilis, I. pusilla, and I.? succincta), and one species of Keo kukia (the type species for the genus, K. sulcata Carter). Also propos ed and described is a new genus, Adairia, with its type species Produc tus (Marginifera) adairensis Drake. All these species of Inflatia, Keo kukia, and Adairia have biostratigraphically restricted ranges within the Meramecian and Chesterian sequence in the Ozark region.