Alibrotus H. Milne Edwards, 1840 accepted as Pseudalibrotus Della Valle, 1893 accepted as Onisimus Boeck, 1871 (additional source)
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 leucopis (G.O. Sars, 1879) accepted as Onisimus leucopis (G.O. Sars, 1879) (source of synonymy)
Boeckosimus normani (G.O. Sars, 1891) accepted as Onisimus normani G.O. Sars, 1891 (new combination reference)
Boeckosimus sextonae (Chevreux, 1926) accepted as Onisimus sextonae (Chevreux, 1926) (additional source)
Boeckosimus simus (Gurjanova, 1962) accepted as Onisimus simus Gurjanova, 1962 (new combination reference)
Onisimus Boeck, 1871 (additional source)
Onisimus abyssi Oldevig, 1959 (additional source)
Onisimus affinis Hansen, 1887 (source of synonymy)
Onisimus barentsi (Stebbing, 1894) (additional source)
Onisimus brevicaudatus Hansen, 1887 (source of synonymy)
Onisimus caricus Hansen, 1887 (source of synonymy)
Onisimus caspius (G.O. Sars, 1896) (basis of record)
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 leucopis (G.O. Sars, 1879) (additional source)
Onisimus litoralis (Krøyer, 1845) (additional source)
Onisimus normani G.O. Sars, 1891 (additional source)
Onisimus platyceras (G.O. Sars, 1896) (new combination reference)
Onisimus plautus (Krøyer, 1845) (new combination reference)
Onisimus sextoni (Chevreux, 1926) accepted as Onisimus sextonae (Chevreux, 1926) (additional source)
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)
Pseudalibrotus Della Valle, 1893 accepted as Onisimus Boeck, 1871 (source of synonymy)