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)
Acmira catherinae (Laubier, 1967) represented as Aricidea (Acmira) catherinae Laubier, 1967 (additional source)
Adalaria proxima (Alder & Hancock, 1854) (additional source)
Aeginina longicornis (Krøyer, 1843) (additional source)
Aequorea albida A. Agassiz, 1862 (additional source)
Aeverrillia setigera (Hincks, 1887) (basis of record)
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)
Ampelisca vadorum Mills, 1963 (additional source)
Ampharete acutifrons (Grube, 1860) (additional source)
Ampharete cirrata Webster & Benedict, 1887 (additional source)
Ampharete trilobata Webster & Benedict, 1887 (basis of record)
Amphipholis squamata (Delle Chiaje, 1828) (additional source)
Amphiporeia lawrenciana Shoemaker, 1929 (additional source)
Amphiporus angulatus (Müller, 1774) (additional source)
Amphiporus bioculatus sensu Verrill, 1892 (additional source)
Amphiporus caecus Verrill, 1892 (additional source)
Amphiporus frontalis Verrill, 1892 (additional source)
Amphiporus heterosorus Verrill, 1892 (additional source)
Amphiporus lactifloreus (Johnston, 1828) (additional source)
Amphitrite brunnea (Stimpson, 1853) (basis of record)
Amphitrite cirrata Müller, 1776 (additional source)
Amphitrite johnstoni Malmgren, 1866 accepted as Neoamphitrite figulus (Dalyell, 1853) (additional source)
Amphitrite ornata (Leidy, 1855) (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 simplex A. d'Orbigny, 1853 (additional source)
Anonyx lilljeborgi Boeck, 1871 (additional source)
Anonyx sarsi Steele & Brunel, 1968 (additional source)
Anoplodactylus lentus Wilson, 1878 (additional source)
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 nolani Webster & Benedict, 1887 (basis of record)
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 castanea (Say, 1822) accepted as Isocrassina castanea (Say, 1822) (additional source)
Astarte elliptica (T. Brown, 1827) accepted as Tridonta elliptica (T. Brown, 1827) (additional source)
Astarte undata A. Gould, 1841 (additional source)
Asterias forbesi (Desor, 1848) (additional source)
Asterias rubens Linnaeus, 1758 (additional source)
Astrotorhynchus bifidus (McIntosh, 1874) Graff, 1905 (additional source)
Astyris lunata (Say, 1826) (additional source)
Astyris rosacea (A. Gould, 1840) (additional source)
Aulactinia stella (Verrill, 1864) (additional source)
Aurelia aurita (Linnaeus, 1758) (additional source)
Autolytus prolifera (O.F. Müller, 1788) accepted as Myrianida prolifera (O.F. Müller, 1788) (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)
Bostrichobranchus pilularis (Verrill, 1871) (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 granosa Stimpson, 1853 (additional source)
Brada sublaevis Stimpson, 1853 (basis of record)
Brada villosa (Rathke, 1843) accepted as Bradabyssa villosa (Rathke, 1843) (additional source)
Buccinum ciliatum (O. Fabricius, 1780) (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 groenlandica Levinsen, 1893 (additional source)
Campanularia volubilis (Linnaeus, 1758) (additional source)
Cancer borealis Stimpson, 1859 (additional source)
Cancer irroratus Say, 1817 (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)
Caprella unica Mayer, 1903 (additional source)
Carcinus maenas (Linnaeus, 1758) (additional source)
Caridion gordoni (Spence Bate, 1858) (additional source)