Onchidoris is a genus of dorid nudibranchs in the family Onchidorididae. One of its members is known to prey on barnacles and the others eat bryozoans. The radula contains a rachidian tooth when fully developed, but this is vestigial in some species. Species within the genus Onchidoris include: Many authors prefer Onchidorus Blainville, 1816 as the valid name for the genus, changed to Onchidoris (Winckworth, 1932; Bouchet & Tardy, 1976; Thompson & Brown, 1976; Cattaneo & Barletta, 1984). According to Pruvot-Fol (1954) however this latter is a nomen nudum, while the elder synonym Villiersia is a nomen oblitum (see also Abbott, 1974). This is why Odhner (1907), Pruvot-Fol (1954), Swennen (1961) and Abbott (1974) are followed in the use of Lamellidoris Alder & Hancock, 1855.