Abietinaria abietina (Linnaeus, 1758) (additional source)
Abietinaria filicula (Ellis & Solander, 1786) (additional source)
Acanthonotozoma serratum (O. Fabricius, 1780) (additional source)
Acaulis primarius Stimpson, 1853 (additional source)
Acmira catherinae (Laubier, 1967) represented as Aricidea (Acmira) catherinae Laubier, 1967 (additional source)
Agalma elegans (M. Sars, 1846) (additional source)
Aglantha digitalis (O.F. Mueller, 1776) accepted as Aglantha digitale (O. F. Müller, 1776) (additional source)
Alvania pseudoareolata Warén, 1974 (additional source)
Ampelisca macrocephala Liljeborg, 1853 (additional source)
Ampharete acutifrons (Grube, 1860) (additional source)
Ampharete cirrata Webster & Benedict, 1887 (additional source)
Amphipholis squamata (Delle Chiaje, 1828) (additional source)
Amphitrite cirrata Müller, 1776 (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)
Anomia squamula Linnaeus, 1758 accepted as Heteranomia squamula (Linnaeus, 1758) (additional source)
Anonyx lilljeborgi Boeck, 1871 (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)
Aporrhais occidentalis (H. Beck, 1836) accepted as Arrhoges occidentalis (H. Beck, 1836) (additional source)
Arabella iricolor (Montagu, 1804) (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)
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)
Astyris lunata (Say, 1826) (additional source)
Aurelia aurita (Linnaeus, 1758) (additional source)
Bolinopsis infundibulum (O.F. Müller, 1776) (additional source)
Boltenia ovifera (Linnaeus, 1767) (additional source)
Bopyroides hippolytes (Kröyer, 1838) (additional source)
Bostrichobranchus pilularis (Verrill, 1871) (additional source)
Brada setosa Verrill, 1873 accepted as Bradabyssa setosa (Verrill, 1873) (basis of record)
Brada villosa (Rathke, 1843) accepted as Bradabyssa villosa (Rathke, 1843) (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)
Calliostoma occidentale (Mighels & C. B. Adams, 1842) (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 septentrionalis Krøyer, 1838 (additional source)
Cauloramphus cymbaeformis (Hincks, 1877) (additional source)
Celleporella hyalina (Linnaeus, 1767) (additional source)
Cerastoderma pinnulatum (Conrad, 1831) accepted as Parvicardium pinnulatum (Conrad, 1831) (additional source)
Cerebratulus lacteus (Leidy, 1851) (additional source)
Cerianthus borealis Verrill, 1873 accepted as Pachycerianthus borealis (Verrill, 1873) (additional source)
Chaetozone setosa Malmgren, 1867 (additional source)
Chiridota laevis (O. Fabricius, 1780) (additional source)
Cirratulus cirratus (O. F. Müller, 1776) (additional source)
Clymenella torquata (Leidy, 1855) (additional source)
Clytia hemisphaerica (Linnaeus, 1767) (additional source)
Colus islandicus (Mohr, 1786) (additional source)
Colus pubescens (A. E. Verrill, 1882) (additional source)
Colus pygmaeus (A. Gould, 1841) (additional source)
Corymorpha pendula L. Agassiz, 1862 (additional source)
Cossura longocirrata Webster & Benedict, 1887 (additional source)
Crangon septemspinosa Say, 1818 (additional source)
Crisia eburnea (Linnaeus, 1758) (additional source)
Crossaster papposus (Linnaeus, 1767) (additional source)
Ctenodiscus crispatus (Bruzelius, 1805) (additional source)
Curtitoma violacea (Mighels & C. B. Adams, 1842) (additional source)
Cuspidaria pellucida (W. Stimpson, 1853) (additional source)
Cyanea capillata (Linnaeus, 1758) (additional source)
Cyclocardia borealis (Conrad, 1832) (additional source)
Cylichna occulta (Mighels & C. B. Adams, 1842) accepted as Cylichnoides occultus (Mighels & C. B. Adams, 1842) (additional source)
Dendrobeania murrayana (Bean in Johnston, 1847) (additional source)
Diastylis lucifera (Krøyer, 1837) (additional source)
Dichelopandalus leptocerus (Smith, 1881) (additional source)
Didemnum albidum (Verrill, 1871) (additional source)
Diphasia fallax (Johnston, 1847) (additional source)
Dodecaceria concharum Örsted, 1843 (additional source)
Dosima fascicularis (Ellis & Solander, 1786) (additional source)
Drilonereis longa Webster, 1879 (additional source)
Drilonereis magna Webster & Benedict, 1887 (additional source)
Ectopleura larynx (Ellis & Solander, 1786) (additional source)
Ephesiella minuta (Webster & Benedict, 1887) accepted as Sphaerodoropsis minuta (Webster & Benedict, 1887) accepted as Sphaerodoridium minutum (Webster & Benedict, 1887) (additional source)
Epimeria loricata G. O. Sars, 1879 represented as Epimeria (Epimeria) loricata G.O. Sars, 1879 (additional source)
Eteone flava (Fabricius, 1780) (additional source)
Eteone heteropoda Hartman, 1951 accepted as Hypereteone heteropoda (Hartman, 1951) (additional source)
Eteone lactea Claparède, 1868 accepted as Hypereteone lactea (Claparède, 1868) (additional source)
Eteone longa (Fabricius, 1780) (additional source)
Eualus gaimardii (H. Milne Edwards, 1837) (additional source)
Eucratea loricata (Linnaeus, 1758) (additional source)
Eudendrium capillare Alder, 1856 (additional source)
Eulalia bilineata (Johnston, 1840) (additional source)
Eulalia viridis (Linnaeus, 1767) (additional source)
Eulimella polita (A. E. Verrill, 1872) (additional source)
Eunice pennata (Müller, 1776) (additional source)
Eunoe nodosa (M. Sars, 1861) (additional source)
Euphrosine borealis Örsted, 1843 (additional source)

Cobscook Bay for Abietinaria abietina (Linnaeus, 1758) 
Cobscook Bay for Abietinaria filicula (Ellis & Solander, 1786) 
Cobscook Bay for Acanthonotozoma serratum (O. Fabricius, 1780) 
Cobscook Bay for Acaulis primarius Stimpson, 1853 
Cobscook Bay for Acmira catherinae (Laubier, 1967) 
Cobscook Bay for Agalma elegans (M. Sars, 1846) 
Cobscook Bay for Aglantha digitalis (O.F. Mueller, 1776) 
Cobscook Bay for Alvania pseudoareolata Warén, 1974 
Cobscook Bay for Ampelisca macrocephala Liljeborg, 1853 
Cobscook Bay for Ampharete acutifrons (Grube, 1860) 
Cobscook Bay for Ampharete cirrata Webster & Benedict, 1887 
Cobscook Bay for Amphipholis squamata (Delle Chiaje, 1828) 
Cobscook Bay for Amphitrite cirrata Müller, 1776 
Cobscook Bay for Anaitides groenlandica (Örsted, 1842) 
Cobscook Bay for Anaitides maculata (Linnaeus, 1767) 
Cobscook Bay for Anaitides mucosa (Örsted, 1843) 
Cobscook Bay for Anomia simplex A. d'Orbigny, 1853 
Cobscook Bay for Anomia squamula Linnaeus, 1758 
Cobscook Bay for Anonyx lilljeborgi Boeck, 1871 
Cobscook Bay for Anonyx nugax (Phipps, 1774) 
Cobscook Bay for Anoplodactylus lentus Wilson, 1878 
Cobscook Bay for Antalis entalis (Linnaeus, 1758) 
Cobscook Bay for Aphrodita aculeata Linnaeus, 1758  (doubtful)
Cobscook Bay for Aphrodita hastata Moore, 1905 
Cobscook Bay for Apistobranchus tullbergi (Théel, 1879) 
Cobscook Bay for Aplidium glabrum (Verrill, 1871) 
Cobscook Bay for Aplidium pallidum (Verrill, 1871) 
Cobscook Bay for Aporrhais occidentalis (H. Beck, 1836) 
Cobscook Bay for Arabella iricolor (Montagu, 1804) 
Cobscook Bay for Arctica islandica (Linnaeus, 1767) 
Cobscook Bay for Aricidea nolani Webster & Benedict, 1887 
Cobscook Bay for Aricidea quadrilobata Webster & Benedict, 1887 
Cobscook Bay for Artacama proboscidea Malmgren, 1866 
Cobscook Bay for Astarte elliptica (T. Brown, 1827) 
Cobscook Bay for Astarte subaequilatera G. B. Sowerby II, 1854 
Cobscook Bay for Astarte undata A. Gould, 1841 
Cobscook Bay for Asterias forbesi (Desor, 1848) 
Cobscook Bay for Astyris lunata (Say, 1826) 
Cobscook Bay for Bathypolypus bairdii (A. E. Verrill, 1873) 
Cobscook Bay for Bolinopsis infundibulum (O.F. Müller, 1776) 
Cobscook Bay for Boltenia ovifera (Linnaeus, 1767) 
Cobscook Bay for Bopyroides hippolytes (Kröyer, 1838) 
Cobscook Bay for Bostrichobranchus pilularis (Verrill, 1871) 
Cobscook Bay for Brada setosa Verrill, 1873 
Cobscook Bay for Brada villosa (Rathke, 1843) 
Cobscook Bay for Buccinum undatum Linnaeus, 1758 
Cobscook Bay for Byblis gaimardi (Krøyer, 1846) 
Cobscook Bay for Byblis serrata S.I. Smith, 1873 
Cobscook Bay for Caberea ellisii (Fleming, 1814) 
Cobscook Bay for Caecognathia elongata (Krøyer, 1847) 
Cobscook Bay for Calathura brachiata (Stimpson, 1853) 
Cobscook Bay for Calliostoma occidentale (Mighels & C. B. Adams, 1842) 
Cobscook Bay for Cancer borealis Stimpson, 1859 
Cobscook Bay for Cancer irroratus Say, 1817 
Cobscook Bay for Candelabrum phrygium (Fabricius, 1780) 
Cobscook Bay for Capitella capitata (Fabricius, 1780) 
Cobscook Bay for Caprella septentrionalis Krøyer, 1838 
Cobscook Bay for Cauloramphus cymbaeformis (Hincks, 1877) 
Cobscook Bay for Celleporella hyalina (Linnaeus, 1767) 
Cobscook Bay for Cerastoderma pinnulatum (Conrad, 1831) 
Cobscook Bay for Cerebratulus lacteus (Leidy, 1851) 
Cobscook Bay for Chaetozone setosa Malmgren, 1867 
Cobscook Bay for Chiridota laevis (O. Fabricius, 1780) 
Cobscook Bay for Chitinopoma serrula (Stimpson, 1853) 
Cobscook Bay for Cirratulus cirratus (O. F. Müller, 1776) 
Cobscook Bay for Clione limacina (Phipps, 1774) 
Cobscook Bay for Clymenella torquata (Leidy, 1855) 
Cobscook Bay for Clytia hemisphaerica (Linnaeus, 1767) 
Cobscook Bay for Colus islandicus (Mohr, 1786) 
Cobscook Bay for Colus pubescens (A. E. Verrill, 1882) 
Cobscook Bay for Colus pygmaeus (A. Gould, 1841) 
Cobscook Bay for Colus stimpsoni (Mörch, 1868) 
Cobscook Bay for Corymorpha pendula L. Agassiz, 1862 
Cobscook Bay for Cossura longocirrata Webster & Benedict, 1887 
Cobscook Bay for Crangon septemspinosa Say, 1818 
Cobscook Bay for Crisia eburnea (Linnaeus, 1758) 
Cobscook Bay for Crossaster papposus (Linnaeus, 1767) 
Cobscook Bay for Cryptonatica affinis (Gmelin, 1791) 
Cobscook Bay for Ctenodiscus crispatus (Bruzelius, 1805) 
Cobscook Bay for Curtitoma violacea (Mighels & C. B. Adams, 1842) 
Cobscook Bay for Cuspidaria pellucida (W. Stimpson, 1853) 
Cobscook Bay for Cyclocardia borealis (Conrad, 1832) 
Cobscook Bay for Cylichna alba (T. Brown, 1827) 
Cobscook Bay for Cylichna occulta (Mighels & C. B. Adams, 1842) 
Cobscook Bay for Dendrobeania murrayana (Bean in Johnston, 1847) 
Cobscook Bay for Diastylis lucifera (Krøyer, 1837) 
Cobscook Bay for Dichelopandalus leptocerus (Smith, 1881) 
Cobscook Bay for Didemnum albidum (Verrill, 1871) 
Cobscook Bay for Diphasia fallax (Johnston, 1847) 
Cobscook Bay for Dodecaceria concharum Örsted, 1843 
Cobscook Bay for Dosima fascicularis (Ellis & Solander, 1786) 
Cobscook Bay for Drilonereis longa Webster, 1879 
Cobscook Bay for Drilonereis magna Webster & Benedict, 1887 
Cobscook Bay for Ectopleura larynx (Ellis & Solander, 1786) 
Cobscook Bay for Ennucula tenuis (Montagu, 1808) 
Cobscook Bay for Ephesiella minuta (Webster & Benedict, 1887) 
Cobscook Bay for Epimeria loricata G. O. Sars, 1879 
Cobscook Bay for Eteone flava (Fabricius, 1780) 
Cobscook Bay for Eteone heteropoda Hartman, 1951 
Cobscook Bay for Eteone lactea Claparède, 1868