The generic classification of family Onuphidae is discussed. Three new genera are described: Notonuphis, Aponuphis and Neonuphis. The genus Leptoecia is reestablished. The genus Paranorthia is considered as a synonym of Rhamphobrachium and Paradiopatra; the genus Paraonuphis - as a synonym of Hyalinoecia and Parhyalinoecia. The systematic postion and geographical distribution of Onuphidae is discussed. All species are distributed along the continental slope and along the underwater ridges pen?? in the oceanic eutrophical zone. Such type of geographical distribution is named here as "deep-water off slope" distribution.