This study describes the biostratigrapaic distribution of Meramecian conodonts from three measured sections of the Greenbrier Limestone (Meramecian-Lower Chesterian), located in the Greendale and Hurricane Ridge Synclines of southwestern Virginia and southern West Virginia. The Little Valley Formation, Hillsdale Limestone and lower portions of the "Denmar-Gasper" and "Ste. Genevieve" Formations, consisting of rocks deposited in a variety of shallow carbonate-ramp environments, were investigated.

Two new multielement conodont apparatuses were recognized: Kladognathus sp. A and Hindeognathus ("Apatognathus") laevipostica. Elements of Kladognathus sp. A are morphologically distinct from homologous elements of the K. levis-K. tenuis group. Evolutionary change from K. levis to K. tenuis is marked by slight Sa and Sb element changes, and the addition of an X element, DE Lambdagnathus fragilidens. Species of Kladognathus are promising Meramecian biostratigraphic markers. Also recognized in this study are species of: Cavusgqnathus, Gnathodus, Hindeodus, Idioprioniodus, Lochriea, Rhachistognathus, “Spathognathodus," Synprioniodina? and Taphrognathus.

Meramecian formations in the study area can be correlated with the Mississippian stratotype (Illinois Basin) based on the following zones: Taphrognathus varians - "Apatognathus," "A." scalenus - Cavusgnathus aad Gnathodus bilineatus - Cavusgnathus charactus.

Southward thickening of the "A." scalenus zone from the Hurricane Ridge Syncline (11 m) to the Greendale Syncline (180-200 m) reflects higher rates of sedimentation and subsidence in the depositional area of the latter. In addition, thinness of the zone in the Hurricane Ridge Syncline may be due to a hiatus between this zone and the younger G. bilineatus zone. This hiatus is not indicated by conodont faunas from the Greendale Syncline, which preserves a more complete Meramecian biostratigraphic record.

Conodont and litahologic evidence for a coeval hiatus exists in other areas of eastern North America: the Illinois Basin stratotype, eastern Kentucky, Southern Ohio and eastern Tennessee.