A species of the genus Pterostichus Bonelli, Pterostichus barri new species, is described from specimens collected in the Appalachian Mountains. It belongs to the subgenus Feronina Casey and differs from the only other species included in that subgenus, P. palmi Schaeffer, in having three (instead of two) discal setae on elytral interval 3 and the median lobe of the aedeagus is more robust with the apical lamella shorter. Pterostichus barri differs from P. (Paraferonia) lubricus LeConte, a morphologically similar species also living in the Appalachian Mountains, in having the elytral striae more impressed, particularly the lateral ones, the last visible sternum of the male with a small, median protuberance, the median lobe rounded between the basal bulb and the shaft, and the right paramere elongate apically.