ABSTRACT: Recent development ofmore global correlations of late Middle through mid-Late Pennsylvanian marine cyclothems in the MidcontinentBasin ofNorthAmericawith similar cyclic successions in theMoscow andDonets basins of eastern Europe,make it appropriate to establish a more accurate correlation of the Midcontinent cyclothems with those in the Illinois and Appalachian basins, where they are separated by fossiliferous terrestrial strata.Marine units in the lowerConemaughGroup of theNorthernAppalachian Basin contain conodont faunas that are similar to those described from the Midcontinent succession.Updated brief descriptions and illustrations of these Appalachian faunas allow direct correlation of these Appalachian marine units with the major marine cyclothems of the Midcontinent and Illinois basins. These faunas also clarify the correlation of named units among the states of the Northern Appalachian Basin, and thus correct a long-standing miscorrelation of the Pine Creek Limestone of Pennsylvania with the Cambridge Limestone of Ohio. The Pine Creek Limestone contains a distinctive conodont fauna that underpins its correlation with the Upper Brush Creek Limestone of Ohio, while the Cambridge Limestone contains a younger fauna that allows its correlation with the Nadine Limestone of Pennsylvania. The Brush Creek Limestone of Pennsylvania contains a distinctive conodont fauna that indicates its correlation with only the Lower Brush Creek Limestone of Ohio. Clarification of the correlations of these marine units from the Appalachian Basin to the Midcontinent Basin will better constrain the correlations of terrestrial fossil localities in the Appalachian and Illinois basins with the global marine time scale.