• Acanthicolepis asperrima (M. Sars, 1861)
• Aceros phyllonyx (M. Sars, 1858) accepted as Arrhis phyllonyx (M. Sars, 1858)
• Acrocnida neapolitana (M. Sars, 1857) accepted as Acrocnida brachiata (Montagu, 1804)
• Actaeon minutum M. Sars, 1835 accepted as Elysia viridis (Montagu, 1804)
• Aega ventrosa M. Sars, 1859 accepted as Aegiochus ventrosa (M. Sars, 1859)
• Aegiochus ventrosa (M. Sars, 1859)
• Aeolidia verrucosa M. Sars, 1829 accepted as Coryphella verrucosa (M. Sars, 1829)
• Agalma elegans (M. Sars, 1846)
• Agalmoides elegans (M. Sars, 1846) accepted as Agalmopsis elegans M. Sars, 1846 accepted as Agalma elegans (M. Sars, 1846)
• Agalmopsis elegans M. Sars, 1846 accepted as Agalma elegans (M. Sars, 1846)
• Alentia gelatinosa (M. Sars, 1835)
• Alitta virens (M. Sars, 1835)
• Ampharete borealis (M. Sars, 1856)
• Ampharete finmarchica (M. Sars, 1865)
• Amphicteis gunneri (M. Sars, 1835)
• Amphithoe macrocephala M. Sars, 1858 accepted as Apherusa macrocephala (M. Sars, 1858)
• Amphithoe serraticornis M. Sars, 1858 accepted as Calliopius laeviusculus (Krøyer, 1838)
• Amphitrite gunneri M. Sars, 1835 accepted as Amphicteis gunneri (M. Sars, 1835)
• Amphiura abyssicola M. Sars, 1861 accepted as Ophiactis abyssicola (M. Sars, 1861)
• Amphiura neapolitana M. Sars, 1857 accepted as Acrocnida brachiata (Montagu, 1804)
• Amphiura virens M. Sars, 1859 accepted as Ophiactis virens (M. Sars, 1859)
• Ampithoe fulvocincta M. Sars, 1858 accepted as Halirages fulvocincta (M. Sars, 1858) accepted as Halirages fulvocinctus (M. Sars, 1858)
• Ampithoe latipes M. Sars, 1858 accepted as Stenopleustes latipes (M. Sars, 1858)
• Ampithoe parasitica M. Sars, 1858 accepted as Epimeria parasitica (M. Sars, 1858) accepted as Epimeria (Epimeria) parasitica (M. Sars, 1858)
• Antalis agilis (M. Sars, 1872)
• Antinoe mollis (M. Sars in G.O. Sars, 1872) accepted as Austrolaenilla mollis (Sars, 1872)
• Antinoella mollis (M. Sars in G.O. Sars, 1872) accepted as Austrolaenilla mollis (Sars, 1872)
• Apherusa macrocephala (M. Sars, 1858)
• Aplysia guttata M. Sars, 1839 accepted as Aplysia punctata (Cuvier, 1803)
• Apseudes (Apseudes) spinosus (M. Sars, 1858) accepted as Apseudes spinosus (M. Sars, 1858)
• Apseudes spinosus (M. Sars, 1858)
• Apseudes spinosus spinosus (M. Sars, 1858)
• Archaster arcticus (M. Sars, 1851) accepted as Leptychaster arcticus (M. Sars, 1851)
• Arctonula arctica (M. Sars, 1851)
• Aricia norvegica M. Sars in G.O. Sars, 1872 accepted as Phylo norvegica (M. Sars in G.O. Sars, 1872)
• Arrhis phyllonyx (M. Sars, 1858)
• Arrhis phyllonyx phyllonyx (M. Sars, 1858) represented as Arrhis phyllonyx (M. Sars, 1858)
• Asteracanthion muelleri M. Sars, 1846 accepted as Asterias muelleri (M. Sars, 1846) accepted as Leptasterias (Leptasterias) muelleri muelleri (M. Sars, 1846)
• Asteracanthion mülleri M. Sars, 1846 accepted as Leptasterias (Leptasterias) muelleri muelleri (M. Sars, 1846)
• Asterias muelleri (M. Sars, 1846) accepted as Leptasterias (Leptasterias) muelleri muelleri (M. Sars, 1846)
• Asterias mülleri (M. Sars, 1846) accepted as Leptasterias (Leptasterias) muelleri (M. Sars, 1846)
• Astropecten arcticus M. Sars, 1851 accepted as Leptychaster arcticus (M. Sars, 1851)
• Asychis biceps (M. Sars, 1861) accepted as Chirimia biceps biceps (Sars, 1861)
• Axinulus (Genaxinus) eumyarius (M. Sars, 1870) accepted as Genaxinus eumyarius (M. Sars, 1870)
• Axinulus eumyarius (M. Sars, 1870) accepted as Genaxinus eumyarius (M. Sars, 1870)
• Axinus eumyarius M. Sars, 1870 accepted as Genaxinus eumyarius (M. Sars, 1870)
• Axinus pusillus M. Sars, 1864 accepted as Axinulus croulinensis (Jeffreys, 1847)
• Bathyplotes natans (M. Sars, 1868)
• Boreophausia raschii (M. Sars, 1863) accepted as Thysanoessa raschii (M. Sars, 1863)
• Branchiomma inconspicua (M. Sars in G.O. Sars, 1872)
• Bulla vitrea M. Sars, 1866 accepted as Philine confusa Ohnheiser & Malaquias, 2013 accepted as Laona confusa (Ohnheiser & Malaquias, 2013)
• Bullaea granulosa M. Sars, 1835 accepted as Philine scabra (O. F. Müller, 1784) accepted as Hermania scabra (O. F. Müller, 1784)
• Cadulus subfusiformis (M. Sars, 1865)
• Calycella plicatilis (M. Sars, 1863) accepted as Stegopoma plicatile (Sars, 1863) accepted as Ptychogena crocea Kramp & Damas, 1925
• Campanularia abietina M. Sars, 1851 accepted as Grammaria abietina (Sars, 1851)
• Campanularia exigua (M. Sars, 1857) accepted as Laomedea exigua M. Sars, 1857
• Campanularia fruticosa M. Sars, 1851 accepted as Lafoea fruticosa (Sars, 1851) accepted as Lafoea dumosa (Fleming, 1820)
• Campanularia volubiliformis M. Sars, 1857 accepted as Clytia hemisphaerica (Linnaeus, 1767)
• Capulacmaea M. Sars, 1859 accepted as Piliscus Lovén, 1859
• Capulacmaea radiata (M. Sars, 1851) accepted as Piliscus commodus (Middendorff, 1851)
• Capulus radiatus M. Sars, 1851 accepted as Piliscus commodus (Middendorff, 1851)
• Chaetopterus norvegicus M. Sars, 1835
• Chirimia biceps (M. Sars, 1861)
• Chone longocirrata M. Sars in G.O. Sars, 1872 accepted as Chone duneri Malmgren, 1867
• Clymene (Praxillella) affinis (M. Sars in G.O. Sars, 1872) accepted as Praxillella affinis (M. Sars in G.O. Sars, 1872)
• Clymene affinis M. Sars in G.O. Sars, 1872 accepted as Praxillella affinis (M. Sars in G.O. Sars, 1872)
• Clymene planiceps M. Sars in G.O. Sars, 1872 accepted as Isocirrus planiceps (M. Sars in G.O. Sars, 1872)
• Clytia gracilis (M. Sars, 1851)
• Colobocephalus M. Sars, 1870
• Colobocephalus costellatus M. Sars, 1870
• Colpodaspis M. Sars, 1870
• Colpodaspis pusilla M. Sars, 1870
• Corymorpha M. Sars, 1835
• Corymorpha annulicornis M. Sars, 1859 accepted as Euphysa aurata Forbes, 1848
• Corymorpha glacialis M. Sars, 1860
• Corymorpha nutans M. Sars, 1835
• Coryne lovenii (M. Sars, 1846) accepted as Sarsia lovenii (M. Sars, 1846)
• Coryne tubulosa (M. Sars, 1835) accepted as Sarsia tubulosa (M. Sars, 1835)
• Coryphella verrucosa (M. Sars, 1829)
• Crangon echinulatus M. Sars, 1862 accepted as Philocheras echinulatus (M. Sars, 1862)
• Crangon norvegicus M. Sars, 1861 accepted as Pontophilus norvegicus (Sars, 1861)
• Crisia denticulata var. arctica M. Sars, 1863
• Cucumaria dicquemarii M. Sars, 1857 accepted as Ocnus grubei (von Marenzeller, 1874) accepted as Pseudocnus grubei (von Marenzeller, 1874) accepted as Pseudocnus grubii (von Marenzeller, 1874)
• Cuneolaria elegans (M. Sars, 1846) accepted as Agalma elegans (M. Sars, 1846)
• Cuspidaria arctica (M. Sars, 1859)
• Cydippe plumosa M. Sars, 1859 accepted as Hormiphora hormiphora (Gegenbaur, 1856)
• Cylichna propinqua M. Sars, 1858 accepted as Cylichna occulta (Mighels & C. B. Adams, 1842) accepted as Cylichnoides occultus (Mighels & C. B. Adams, 1842)
• Cylichna propinqva M. Sars, 1858 accepted as Cylichna propinqua M. Sars, 1858 accepted as Cylichna occulta (Mighels & C. B. Adams, 1842) accepted as Cylichnoides occultus (Mighels & C. B. Adams, 1842)
• Cypraea norvegica M. Sars, 1835 accepted as Trivia arctica (Pulteney, 1799)
• Cytaeis octopunctata M. Sars, 1835 accepted as Rathkea octopunctata (M. Sars, 1835)
• Dasychone inconspicua M. Sars in G.O. Sars, 1872 accepted as Branchiomma inconspicua (M. Sars in G.O. Sars, 1872)
• Defrancia lucernaria M. Sars, 1851 accepted as Infundibulipora lucernaria (Sars, 1851)
• Dentalium (Antalis) agile M. Sars, 1872 accepted as Antalis agilis (M. Sars, 1872)
• Dentalium abyssorum M. Sars, 1859 accepted as Antalis occidentalis (W. Stimpson, 1851)
• Dentalium agile M. Sars, 1872 accepted as Antalis agilis (M. Sars, 1872)
• Dentalium vitreum M. Sars, 1851 accepted as Siphonodentalium lobatum (G. B. Sowerby II, 1860)
• Depastrum cyathiforme (M. Sars, 1846)
• Diaphorodoris luteocincta (M. Sars, 1870)
• Diplopteraster multipes (M. Sars, 1866)
• Diplopteraster multipes multipes (M. Sars, 1866)