Camallanus ancylodirus Ward and Magath 1916 is redescribed, based on examination of syntypes. This species differs from C. oxycephalus Ward and Magath 1916, the only other camallanid described from freshwater fishes of North America, in the size of male worms, number and arrangement of caudal papillae in males, shape of the male caudal end, position of the vulva, and length and shape of the female tail. The host range of C. ancylodirus is not clear from literature reports because the species may have been confused with C. oxycephalus.