Abietinaria abietina (Linnaeus, 1758) (additional source)
Abietinaria filicula (Ellis & Solander, 1786) (additional source)
Acanthodoris pilosa (Abildgaard, 1789) (additional source)
Acanthonotozoma serratum (O. Fabricius, 1780) (additional source)
Acaulis primarius Stimpson, 1853 (additional source)
Achelia spinosa (Stimpson, 1853) (additional source)
Adalaria proxima (Alder & Hancock, 1854) (additional source)
Aeginina longicornis (Krøyer, 1843) (additional source)
Agalma elegans (M. Sars, 1846) (additional source)
Alvania pseudoareolata Warén, 1974 (additional source)
Amblyosyllis finmarchica (Malmgren, 1867) (additional source)
Ampelisca macrocephala Liljeborg, 1853 (additional source)
Ampharete acutifrons (Grube, 1860) (additional source)
Amphipholis squamata (Delle Chiaje, 1828) (additional source)
Amphiporus angulatus (Müller, 1774) (additional source)
Amphiporus bioculatus sensu Verrill, 1892 (additional source)
Amphiporus groenlandicus Örsted, 1843 (additional source)
Amphiporus lactifloreus (Johnston, 1828) (additional source)
Amphitrite cirrata Müller, 1776 (additional source)
Amphitrite johnstoni Malmgren, 1866 accepted as Neoamphitrite figulus (Dalyell, 1853) (additional source)
Anaitides groenlandica (Örsted, 1842) accepted as Phyllodoce groenlandica Örsted, 1842 (additional source)
Anaitides maculata (Linnaeus, 1767) accepted as Phyllodoce maculata (Linnaeus, 1767) (additional source)
Anaitides mucosa (Örsted, 1843) accepted as Phyllodoce mucosa Örsted, 1843 (additional source)
Anomia squamula Linnaeus, 1758 accepted as Heteranomia squamula (Linnaeus, 1758) (additional source)
Anonyx lilljeborgi Boeck, 1871 (additional source)
Anonyx sarsi Steele & Brunel, 1968 (additional source)
Anoplodactylus lentus Wilson, 1878 (additional source)
Aphanostoma sanguineum Beklemischev, 1915 accepted as Pseudactinoposthia sanguineum (Beklemischev, 1915) (basis of record)
Apistobranchus tullbergi (Théel, 1879) (additional source)
Aplidium glabrum (Verrill, 1871) (additional source)
Aplidium pallidum (Verrill, 1871) (additional source)
Arabella iricolor (Montagu, 1804) (additional source)
Arenicola marina (Linnaeus, 1758) (additional source)
Aricidea quadrilobata Webster & Benedict, 1887 represented as Aricidea (Strelzovia) quadrilobata Webster & Benedict, 1887 (additional source)
Artacama proboscidea Malmgren, 1866 (additional source)
Ascidia callosa Stimpson, 1852 (additional source)
Ascidia prunum Müller, 1776 (additional source)
Astarte borealis (Schumacher, 1817) accepted as Tridonta borealis Schumacher, 1817 (additional source)
Astarte elliptica (T. Brown, 1827) accepted as Tridonta elliptica (T. Brown, 1827) (additional source)
Asterias forbesi (Desor, 1848) (additional source)
Asterias rubens Linnaeus, 1758 (additional source)
Astrotorhynchus bifidus (McIntosh, 1874) Graff, 1905 (additional source)
Astyris rosacea (A. Gould, 1840) (additional source)
Aulactinia stella (Verrill, 1864) (additional source)
Aurelia aurita (Linnaeus, 1758) (additional source)
Autolytus cornutus Agassiz, 1862 accepted as Proceraea cornuta (Agassiz, 1862) (additional source)
Autolytus prolifera (O.F. Müller, 1788) accepted as Myrianida prolifera (O.F. Müller, 1788) (additional source)
Autolytus verrilli Marenzeller, 1892 accepted as Epigamia alexandri (Malmgren, 1867) (additional source)
Balanus balanus (Linnaeus, 1758) (additional source)
Balanus crenatus Bruguière, 1789 (additional source)
Bolinopsis infundibulum (O.F. Müller, 1776) (additional source)
Boltenia echinata (Linnaeus, 1767) (additional source)
Boltenia ovifera (Linnaeus, 1767) (additional source)
Bopyroides hippolytes (Kröyer, 1838) (additional source)
Boreotrophon clathratus (Linnaeus, 1767) (additional source)
Boreotrophon truncatus (Strøm, 1768) (additional source)
Botryllus schlosseri (Pallas, 1766) (additional source)
Bougainvillia superciliaris (L. Agassiz, 1849) (additional source)
Bowerbankia gracilis Leidy, 1855 accepted as Amathia gracilis (Leidy, 1855) (additional source)
Brada villosa (Rathke, 1843) accepted as Bradabyssa villosa (Rathke, 1843) (additional source)
Buccinum ciliatum (O. Fabricius, 1780) (additional source)
Buccinum polaris Gray, 1839 accepted as Buccinum polare Gray, 1839 (additional source)
Bugula fulva Ryland, 1960 accepted as Bugulina fulva (Ryland, 1960) (additional source)
Bugula simplex Hincks, 1886 accepted as Bugulina simplex (Hincks, 1886) (additional source)
Byblis gaimardi (Krøyer, 1846) accepted as Byblis gaimardii (Krøyer, 1846) (additional source)
Byblis serrata S.I. Smith, 1873 (additional source)
Caberea ellisii (Fleming, 1814) (additional source)
Caecognathia elongata (Krøyer, 1847) (additional source)
Calathura brachiata (Stimpson, 1853) (additional source)
Calliopius laeviusculus (Krøyer, 1838) (additional source)
Calliostoma occidentale (Mighels & C. B. Adams, 1842) (additional source)
Callopora aurita (Hincks) accepted as Amphiblestrum auritum (Hincks, 1877) (additional source)
Callopora craticula (Alder, 1856) (additional source)
Calycella syringa (Linnaeus, 1767) (additional source)
Campanularia volubilis (Linnaeus, 1758) (additional source)
Candelabrum phrygium (Fabricius, 1780) (additional source)
Capitella capitata (Fabricius, 1780) (additional source)
Caprella linearis (Linnaeus, 1767) (additional source)
Caprella penantis Leach, 1814 (additional source)
Caprella septentrionalis Krøyer, 1838 (additional source)
Carcinus maenas (Linnaeus, 1758) (additional source)
Caridion gordoni (Spence Bate, 1858) (additional source)
Catablema vesicarium (A. Agassiz, 1862) (additional source)
Cauloramphus cymbaeformis (Hincks, 1877) (additional source)
Celleporella hyalina (Linnaeus, 1767) (additional source)
Cephalothrix linearis (Rathke, 1799) (additional source)
Cerebratulus lacteus (Leidy, 1851) (additional source)
Chaetozone setosa Malmgren, 1867 (additional source)
Chiridota laevis (O. Fabricius, 1780) (additional source)
Chiridotea caeca (Say, 1818) accepted as Chiridotea coeca (Say, 1818) (additional source)
Chiridotea tuftsii (Stimpson, 1853) (additional source)
Ciona intestinalis (Linnaeus, 1767) (additional source)
Cirratulus cirratus (O. F. Müller, 1776) (additional source)
Cirrifera cirrifera Sopott, 1972 (additional source)
Clava multicornis (Forsskål, 1775) (additional source)
Clinocardium ciliatum (O. Fabricius, 1780) accepted as Ciliatocardium ciliatum ciliatum (O. Fabricius, 1780) represented as Ciliatocardium ciliatum (O. Fabricius, 1780) (additional source)
Cliona vastifica Hancock, 1849 accepted as Pione vastifica (Hancock, 1849) (additional source)
Clitellio (Clitellio) arenarius (Müller, 1776) (additional source)
Clymenella torquata (Leidy, 1855) (additional source)
Clytia hemisphaerica (Linnaeus, 1767) (additional source)