Actinia coccinea Müller, 1776 accepted as Stomphia coccinea (Müller, 1776) (additional source)
Actinia digitata Müller, 1776 accepted as Hormathia digitata (O.F. Müller, 1776) (additional source)
Actinia mesembryanthemum Ellis & Solander, 1786 accepted as Actinia nigropunctata den Hartog & Ocaña, 2003 (additional source)
Actinia plumosa accepted as Metridium dianthus (Ellis, 1768) (additional source)
Amaroucium incrustatum Sars, 1851 accepted as Synoicum incrustatum (Sars, 1851) (original description)
Amaroucium mutabile Sars, 1851 accepted as Aplidium mutabile (Sars, 1851) (original description)
Amaroucium pomum Sars, 1851 accepted as Synoicum pulmonaria (Ellis & Solander, 1786) (original description)
Ammochares assimilis Sars, 1851 accepted as Owenia assimilis (Sars, 1851) (original description)
Amphitrite eschrichtii Rathke, 1843 accepted as Cistenides granulata (Linnaeus, 1767) (additional source)
Archaster arcticus (M. Sars, 1851) accepted as Leptychaster arcticus (M. Sars, 1851) (original description)
Ascidia loveni Sars, 1851 accepted as Styela coriacea (Alder & Hancock, 1848) (original description)
Astropecten arcticus M. Sars, 1851 accepted as Leptychaster arcticus (M. Sars, 1851) (original description)
Botrylloides aurea Sars, 1851 accepted as Botrylloides aureus Sars, 1851 (original description)
Campanularia abietina M. Sars, 1851 accepted as Grammaria abietina (Sars, 1851) (original description)
Campanularia fruticosa M. Sars, 1851 accepted as Lafoea fruticosa (Sars, 1851) accepted as Lafoea dumosa (Fleming, 1820) (original description)
Capulus radiatus M. Sars, 1851 accepted as Piliscus commodus (Middendorff, 1851) (original description)
Clymene cirrosa Sars, 1851 (original description)
Clymene lumbricalis (Fabricius, 1780) accepted as Nicomache lumbricalis (Fabricius, 1780) (additional source)
Clymene muelleri Sars, 1856 accepted as Proclymene muelleri (Sars, 1856) (additional source)
Dentalium vitreum M. Sars, 1851 accepted as Siphonodentalium lobatum (G. B. Sowerby II, 1860) (original description)
Didemnum roseum Sars, 1851 (original description)
Distomum vitreum Sars, 1851 accepted as Eudistoma vitreum (Sars, 1851) (original description)
Edwardsia duodecimcirrata Sars, 1851 accepted as Halcampa duodecimcirrata (Sars, 1851) (original description)
Euphrosyna armadillo M. Sars, 1851 accepted as Euphrosine armadillo M. Sars, 1851 (original description)
Gonactinia Sars, 1851 (original description)
Gonactinia prolifera (Sars, 1835) (additional source)
Lamellaria glacialis M. Sars, 1851 accepted as Onchidiopsis glacialis (M. Sars, 1851) (original description)
Laomedea gracilis M. Sars, 1851 accepted as Clytia gracilis (M. Sars, 1851) (original description)
Lepralia arctica M. Sars, 1851 accepted as Arctonula arctica (M. Sars, 1851) (original description)
Lepralia patula M. Sars, 1851 accepted as Porella patula (M.Sars, 1851) (original description)
Leptoclinum clavatum Sars, 1851 accepted as Distaplia clavata (Sars, 1851) (original description)
Leptoclinum lividum Sars, 1851 accepted as Distaplia livida (Sars, 1851) (original description)
Littorina arctica var. angulata M. Sars, 1851 accepted as Littorina obtusata (Linnaeus, 1758) (original description)
Littorina arctica var. elatior M. Sars, 1851 accepted as Littorina obtusata (Linnaeus, 1758) (original description)
Myriothela Sars, 1851 accepted as Candelabrum de Blainville, 1830 (original description)
Myriothela arctica M. Sars, 1851 accepted as Candelabrum phrygium (Fabricius, 1780) (original description)
Nerine cirrata M. Sars, 1851 accepted as Laonice cirrata (M. Sars, 1851) (original description)
Notomastus M. Sars, 1851 (original description)
Notomastus latericeus Sars, 1851 (original description)
Nucula pumila Sars, 1851 accepted as Nucula tumidula Malm, 1861 (original description)
Oniscosoma Sars, 1851 accepted as Spinther Johnston, 1845 (original description)
Oniscosoma arcticum Sars, 1851 accepted as Spinther arcticus (M. Sars, 1851) (original description)
Onuphis eschrichti Örsted, 1843 accepted as Nothria conchylega (Sars, 1835) (source of synonymy)
Placostegus politus (Sars, 1851) accepted as Placostegus tridentatus (Fabricius, 1779) (original description)
Sabella crassicornis Sars, 1851 accepted as Bispira crassicornis (Sars, 1851) (original description)
Sabella lucullana Delle Chiaje, 1828 accepted as Branchiomma lucullanum (Delle Chiaje, 1828) (additional source)
Sabella neglecta Sars, 1851 accepted as Potamilla neglecta (Sars, 1851) (original description)
Sabella papillosa Sars, 1851 accepted as Euchone papillosa (Sars, 1851) (original description)
Sabellides Milne Edwards in Lamarck, 1838 accepted as Ampharete Malmgren, 1866 (status source)
Sabellides cristata M. Sars, 1851 accepted as Melinna cristata (M. Sars, 1851) (original description)
Sabellides octocirrata (M. Sars, 1835) accepted as Ampharete octocirrata (Sars, 1835) (new combination reference)
Serpula polita Sars, 1851 accepted as Placostegus tridentatus (Fabricius, 1779) (original description)
Serpula vermicularis non Linnaeus, 1767 sensu Müller, 1789 accepted as Hydroides norvegica Gunnerus, 1768 (additional source)
Sipunculus margaritaceus Sars, 1851 accepted as Golfingia (Golfingia) margaritacea (Sars, 1851) (original description)
Tritonium eburneum M. Sars, 1851 accepted as Liomesus ovum (W. Turton, 1825) (original description)
Tritonium incarnatum M. Sars, 1851 accepted as Retifusus latericeus (Møller, 1842) (original description)
Ulocyathus Sars, 1851 accepted as Flabellum (Ulocyathus) Sars, 1851 (original description)
Ulocyathus arcticus Sars, 1851 accepted as Flabellum (Ulocyathus) macandrewi Gray, 1849 (original description)

Norway for Ammochares assimilis Sars, 1851 
Norwegian Exclusive Economic Zone for Actinia digitata Müller, 1776 
Norwegian Exclusive Economic Zone for Actinia digitata Müller, 1776 
Norwegian Exclusive Economic Zone for Actinia digitata Müller, 1776 
Norwegian Exclusive Economic Zone for Edwardsia duodecimcirrata Sars, 1851 
Norwegian Exclusive Economic Zone for Edwardsia duodecimcirrata Sars, 1851 

 Spelling

 for Sphinter wiréni [misspelling]

Incorrect subsequent spelling of both genus and species. Here in a checklist listing by Bellan (2001). Retained ... [details]