[Summary]. Descriptions are given of four species of Oreoscolex recently transferred to this genus from Notoscolex. All are shown to have the eight setae per segment and multiple caudal nephrostomes diagnostic of the genus. A key to the five species of Oreoscolex in New South Wales, including the type-species O. imparicystis, is given. Occurrence of a further eight species in Tasmania strongly suggests that the genus will also be found in intervening Victoria.