Abyssocucumis Heding, 1942 (additional source)
Abyssocucumis abyssorum (Théel, 1886) (additional source)
Abyssoninoe Orensanz, 1990 (additional source)
Acanthotrochus Danielssen & Koren, 1881 (additional source)
Acanthotrochus mirabilis Danielssen & Koren, 1881 (additional source)
Achlyonice Théel, 1879 (additional source)
Achlyonice myriamae Gebruk, 1997 (additional source)
Actinia Linnaeus, 1767 (additional source)
Aglaophenia Lamouroux, 1812 (additional source)
Alecto Leach, 1815 (additional source)
Alecto eschrichtii Müller, 1841 accepted as Heliometra glacialis (Owen, 1833 ex Leach MS) (additional source)
Alecto phalangium Müller, 1841 accepted as Leptometra phalangium (Müller, 1841) (additional source)
Allantis Hérouard, 1902 accepted as Mesothuria Ludwig, 1894 (additional source)
Amperima Pawson, 1965 (additional source)
Amperima furcata (Hérouard, 1899) (additional source)
Amperima rosea (E. Perrier, 1886) (additional source)
Amphilepis Ljungman, 1867 (additional source)
Amphilepis norvegica (Ljungman, 1865) (additional source)
Amphiocnida Verrill, 1899 accepted as Ophiocentrus Ljungman, 1867 (additional source)
Amphiocnida brachiata (Montagu, 1804) accepted as Acrocnida brachiata (Montagu, 1804) (additional source)
Amphipholis Ljungman, 1866 (additional source)
Amphipholis squamata (Delle Chiaje, 1828) (additional source)
Amphipholis torelli Ljungman, 1872 (additional source)
Amphiura (Acrocnida) accepted as Acrocnida Gislén, 1926 (additional source)
Amphiura (Acrocnida) brachiata (Montagu, 1804) accepted as Acrocnida brachiata (Montagu, 1804) (additional source)
Amphiura (Ophiopeltis) securigera (Düben & Koren, 1846) (additional source)
Amphiura borealis (G.O. Sars, 1872) (additional source)
Amphiura chiajei Forbes, 1843 (additional source)
Amphiura denticulata Koehler, 1896 accepted as Amphiura fragilis Verrill, 1885 (additional source)
Amphiura elegans (Leach, 1815) accepted as Amphipholis squamata (Delle Chiaje, 1828) (additional source)
Amphiura filiformis (O.F. Müller, 1776) (additional source)
Amphiura fragilis Verrill, 1885 (additional source)
Amphiura griegi Mortensen, 1920 (additional source)
Amphiura incana Lyman, 1879 represented as Amphiura (Amphiura) incana Lyman, 1879 (additional source)
Amphiura norvegica Ljungman, 1865 accepted as Amphilepis norvegica (Ljungman, 1865) (additional source)
Amphiura sundevalli (Müller & Troschel, 1842) (additional source)
Ankyroderma Ludwig, 1890, non Danielssen & Koren, 1879 accepted as Molpadia Cuvier, 1817 (additional source)
Ankyroderma affine Danielssen & Koren, 1881 accepted as Molpadia borealis Sars M, 1859 (additional source)
Ankyroderma danielsseni Théel, 1886 accepted as Molpadia musculus Risso, 1826 (additional source)
Ankyroderma hispanicum Petit, 1883 accepted as Molpadia musculus Risso, 1826 (additional source)
Ankyroderma jeffreysii Danielssen & Koren, 1881 accepted as Molpadia jeffreysi (Danielssen & Koren, 1881) accepted as Molpadia borealis Sars M, 1859 (additional source)
Ankyroderma loricatum Perrier R., 1898 accepted as Molpadia musculus Risso, 1826 (additional source)
Ankyroderma maroccanum R. Perrier, 1898 accepted as Molpadia maroccana (R. Perrier, 1898) (additional source)
Ankyroderma perrieri Petit, 1883 accepted as Molpadia musculus Risso, 1826 (additional source)
Anseropoda Nardo, 1834 (additional source)
Anseropoda placenta (Pennant, 1777) (additional source)
Antedon de Fréminville, 1811 (additional source)
Antedon bifida (Pennant, 1777) (additional source)
Antedon gorgonia de Fréminville, 1811 accepted as Antedon bifida bifida (Pennant, 1777) (additional source)
Antedon petasus (Düben & Koren, 1846) (additional source)
Antedon prolixa Sladen in Duncan & Sladen, 1881 accepted as Poliometra prolixa (Sladen, 1881) (additional source)
Antedonidae Norman, 1865 (additional source)
Aora Krøyer, 1845 (additional source)
Aora typica Krøyer, 1845 (additional source)
Arachnida (basis of record)
Archaster sepitus Verrill, 1885 accepted as Cheiraster (Cheiraster) sepitus (Verrill, 1885) (additional source)
Asteracanthion albulus Stimpson, 1853 accepted as Stephanasterias albula (Stimpson, 1853) (additional source)
Asterias brachiata Montagu, 1804 accepted as Acrocnida brachiata (Montagu, 1804) (additional source)
Asterias glacialis Linnaeus, 1758 accepted as Marthasterias glacialis (Linnaeus, 1758) (additional source)
Asterias granularis Retzius, 1783 accepted as Ceramaster granularis (Retzius, 1783) (additional source)
Asterias gunneri Danielssen & Koren, 1883 accepted as Urasterias lincki (Müller & Troschel, 1842) (additional source)
Asterias hyperborea Danielssen & Koren, 1883 accepted as Leptasterias hyperborea (Danielssen & Koren, 1882) (additional source)
Asterias nigra Abildgaard in O.F. Müller, 1789 accepted as Ophiocomina nigra (Abildgaard in O.F. Müller, 1789) (additional source)
Asterias normani Danielssen & Koren, 1883 accepted as Leptasterias hyperborea (Danielssen & Koren, 1882) (additional source)
Asterias ophiura Linnaeus, 1758 accepted as Ophiura ophiura (Linnaeus, 1758) (additional source)
Asterias panopla Stuxberg, 1879 accepted as Icasterias panopla (Stuxberg, 1879) (additional source)
Asterias papposus Linnaeus, 1767 accepted as Solaster papposus (Linnaeus, 1767) accepted as Crossaster papposus (Linnaeus, 1767) (additional source)
Asterias pentaphylla Pennant, 1777 accepted as Ophiothrix fragilis (Abildgaard in O.F. Müller, 1789) (additional source)
Asterias rosea O.F. Müller, 1776 accepted as Linckia rosea (O.F. Müller, 1776) accepted as Stichastrella rosea (O.F. Müller, 1776) (additional source)
Asterias rumphii Parelius, 1768 accepted as Solaster endeca (Linnaeus, 1771) (additional source)
Asterias spinosa Pennant, 1777 accepted as Marthasterias glacialis (Linnaeus, 1758) (additional source)
Asterias stellionura Valenciennes (MS) in Perrier, 1869 accepted as Urasterias lincki (Müller & Troschel, 1842) (basis of record)
Asterias stellionura Valenciennes (MS) in Perrier, 1869 accepted as Urasterias lincki (Müller & Troschel, 1842) (source of synonymy)
Asterina Nardo, 1834 (additional source)
Asterina gibbosa (Pennant, 1777) (additional source)
Asterina minuta Nardo, 1834 accepted as Asterina gibbosa (Pennant, 1777) (additional source)
Asterina phylactica Emson & Crump, 1979 (additional source)
Asteronyx Müller & Troschel, 1842 (additional source)
Asteronyx loveni Müller & Troschel, 1842 (additional source)
Asteropseidae Hotchkiss & Clark, 1976 (basis of record)
Asteropsis capreensis Gasco, 1876 accepted as Marginaster capreensis (Gasco, 1876) (additional source)
Astropecten Gray, 1840 (additional source)
Astropecten irregularis (Pennant, 1777) (additional source)
Astropecten irregularis irregularis (Pennant, 1777) (additional source)
Astropecten pallidus Danielssen & Koren, 1877 accepted as Bathybiaster vexillifer (Wyville Thomson, 1873) (additional source)
Astropecten sphenoplax Bell, 1892 accepted as Persephonaster sphenoplax (Bell, 1892) (additional source)
Astropecten tenuispinus Düben & Koren, 1846 accepted as Archaster tenuispinus (Düben & Koren, 1846) accepted as Pontaster tenuispinus (Düben & Koren, 1846) (additional source)
Atelecrinidae Bather, 1899 (additional source)
Atelecrinus Carpenter, 1881 (additional source)
Atelecrinus helgae AH Clark, 1913 (additional source)
Axiognathus squamata (Delle Chiaje, 1829) accepted as Amphipholis squamata (Delle Chiaje, 1828) (additional source)
Bathybiaster Danielssen & Koren, 1883 (additional source)
Bathybiaster vexillifer (Wyville Thomson, 1873) (additional source)
Bathycrinidae Bather, 1899 (additional source)
Bathycrinus Thomson, 1872 (additional source)
Bathycrinus carpenterii (Danielssen & Koren, 1877) (additional source)
Bathycrinus gracilis Thomson, 1872 (additional source)
Bathyplotes Östergren, 1896 (additional source)
Bathyplotes fallax Östergren, 1896 accepted as Bathyplotes natans (M. Sars, 1868) (additional source)
Bathyplotes heterostylides Heding, 1942 accepted as Bathyplotes natans (M. Sars, 1868) (additional source)

English squirrel's tail for Sertularia argentea Linnaeus, 1758