Boeckosimus J.L. Barnard, 1969 accepted as Onisimus Boeck, 1871 (additional source)
Boeckosimus edwardsii (Krøyer, 1846) accepted as Onisimus edwardsii (Krøyer, 1846) (additional source)
Boeckosimus krassini (Gurjanova, 1951) accepted as Onisimus krassini Gurjanova, 1951 accepted as Onisimus barentsi (Stebbing, 1894) (source of synonymy)
Boeckosimus normani (G.O. Sars, 1891) accepted as Onisimus normani G.O. Sars, 1891 (new combination reference)
Boeckosimus sibiricus (Brüggen, 1909) accepted as Onisimus sibiricus Brüggen, 1909 (new combination reference)
Boeckosimus simus (Gurjanova, 1962) accepted as Onisimus simus Gurjanova, 1962 (new combination reference)
Boeckosimus turgidus (G.O. Sars, 1879) accepted as Onisimus turgidus (G.O. Sars, 1879) (new combination reference)
Onisimus Boeck, 1871 (additional source)
Onisimus affinis Hansen, 1887 (source of synonymy)
Onisimus barentsi (Stebbing, 1894) (additional source)
Onisimus botkini Birula, 1897 (new combination reference)
Onisimus brevicaudatus Hansen, 1887 (source of synonymy)
Onisimus caricus Hansen, 1887 (source of synonymy)
Onisimus crassini Gorbunov, 1946 (status source)
Onisimus derjugini Gurjanova, 1929 (source of synonymy)
Onisimus edwardsii (Krøyer, 1846) (additional source)
Onisimus glacialis (G.O. Sars, 1900) (new combination reference)
Onisimus litoralis (Krøyer, 1845) (additional source)
Onisimus normani G.O. Sars, 1891 (additional source)
Onisimus plautus (Krøyer, 1845) (new combination reference)
Onisimus turgidus (G.O. Sars, 1879) (additional source)
Paronesimus Pirlot, 1933 accepted as Onisimus Boeck, 1871 (additional source)
Paronesimus barentsi Stebbing, 1894 accepted as Onisimus barentsi (Stebbing, 1894) (redescription)