Halgerda maricola S.J. Fahey & T.M. Gosliner,2001
Alloiodoris marmorata L.S.R. Bergh, 1904
Geitodoris mavis (Er. Marcus & Ev. Marcus,1967)
Baptodoris mimetica T.M. Gosliner, 1991
Asteronotus mimeticus T.M. Gosliner & Á. Valdés,2002
Montereina modesta (L.S.R. Bergh, 1877)
Atagema molesta (M.C. Miller, 1989)
Geitodoris mollina W.H. Dall & C.T. Simpson,1901
Atagema monsoni C.N.E. Eliot, 1903
Diaulula morosa L.S.R. Bergh, 1907
Discodoris mortenseni (Er. Marcus & Ev. Marcus,1963)
Paradoris mulciber (Ev. Marcus, 1971)
Peltodoris mullineri S.V. Millen & H.W. Bertsch,2000
Peltodoris murrea (F.D. Abraham, 1877)
Rostanga muscula (F.D. Abraham, 1877)
Montereina muta (L.S.R. Bergh, 1877)
Discodoris natalensis (C.F.F. von Krauss, 1848)
Thordisa nieseni G.L. Chan & T.M. Gosliner,2007
Kentrodoris nigra J.J. Risbec, 1928
Diaulula nivosa Á. Valdés & H.W. Bertsch,2010
Montereina nobilis (F.M. MacFarland, 1905)
Hoplodoris nodulosa (G.F. Angas, 1864)
Atagema notacristata Y. Camacho-García& T.M. Gosliner, 2008
Montereina notha (L.S.R. Bergh, 1877)
Peltodoris noumeae J.J. Risbec, 1937
Sebadoris nubilosa (W.H. Pease, 1871)
Platydoris ocellata K.M. Dorgan, Á. Valdés& T.M. Gosliner, 2002
Kentrodoris ocelligera (H.F.A. von Ihering)
Geitodoris ohshimai (K. Baba, 1936)
Halgerda okinawa C.H. Carlson & P.J. Hoff,2000
Taringa oleica J.A. Ortea, A.M. Pérez& E.M. Llera, 1982
Thordisa oliva G.L. Chan & T.M. Gosliner,2007
Halgerda onna S.J. Fahey & T.M. Gosliner,2001
Jorunna onubensis J.L. Cervera, J.C. García-Gómez& F.J. García, 1986
Montereina opisthidia (L.S.R. Bergh, 1877)