ABSTRACT: The conodont species Polygnathus tuberculatus Hinde is best known in condensed conodont-bone bed lag deposits in western New York and southern Indiana. These occurrences, containing conodonts ranging from zones of the Middle Givetian Middle varcus (= ansatus) Zone to Lower Frasnian Zone 2, have influenced a postulated range extension above the varcus Zone. However, the occurrence in theKentuckyNew Albany Shale zonal succession indicates that P. tuberculatus may be confined to the Middle varcus Zone. This is supported by the occurrence in the Tully Limestone in Pennsylvania. The species appears to be endemic to eastern North America, with the exception of occurrences in southwest England and the Rhenish Slate Mountains of Germany of a somewhat different morphotype.