Acontiaria Stephenson, 1935 (additional source)
Acthelmis Lütken, 1875 (additional source)
Acthelmis intestinalis (Fabricius, 1780) (additional source)
Actinauge Verrill, 1883 (additional source)
Actinauge abyssorum Carlgren, 1934 (additional source)
Actinauge longicornis (Verrill, 1882) (additional source)
Actinauge richardi (Marion, 1906) (additional source)
Actinauge verrillii McMurrich, 1893 (additional source)
Actinernidae Stephenson, 1922 (additional source)
Actinernus Verrill, 1879 (additional source)
Actinernus michaelsarsi Carlgren, 1918 (additional source)
Actinernus nobilis Verrill, 1879 (additional source)
Actinia cari Delle Chiaje, 1822 (additional source)
Actinia equina (Linnaeus, 1758) (additional source)
Actiniaria (additional source)
Actiniidae Rafinesque, 1815 (additional source)
Actinoscyphia Stephenson, 1920 (additional source)
Actinoscyphia aurelia (Stephenson, 1918) (additional source)
Actinoscyphia saginata (Verrill, 1882) (additional source)
Actinostola Verrill, 1883 (additional source)
Actinostola abyssorum (Danielssen, 1890) (additional source)
Actinostola callosa (Verrill, 1882) (additional source)
Actinostola spetsbergensis Carlgren, 1893 accepted as Glandulactis spetsbergensis (Carlgren, 1893) (additional source)
Actinostolidae Carlgren, 1932 (additional source)
Actinothoe Fischer, 1889 (additional source)
Actinothoe modesta (Verrill, 1866) (additional source)
Actinothoe sphyrodeta (Gosse, 1858) (additional source)
Adamsia palliata (Fabricius, 1779) accepted as Calliactis palliata (Müller, 1776) (additional source)
Adamsia sociabilis Verrill, 1882 accepted as Calliactis sociabilis (Verrill, 1882) (additional source)
Aiptasia Gosse, 1858 (additional source)
Aiptasia couchii Gosse (additional source)
Aiptasia diaphana (Rapp, 1829) accepted as Exaiptasia diaphana (Rapp, 1829) (additional source)
Aiptasiidae Carlgren, 1924 (additional source)
Alicia costae (Panceri, 1868) accepted as Alicia mirabilis Johnson, 1861 (additional source)
Alicia mirabilis Johnson, 1861 (additional source)
Aliciidae Duerden, 1895 (additional source)
Allantactis Danielssen, 1890 (additional source)
Allantactis parasitica Danielssen, 1890 (additional source)
Amphianthus bathybium Hertwig, 1882 (additional source)
Amphianthus crassus (Gravier, 1918) accepted as Gliactis crassa Gravier, 1918 (additional source)
Amphianthus impeditus (Gravier, 1918) accepted as Stephanauge impedita (Gravier, 1918) (additional source)
Amphianthus ingolfi Carlgren, 1942 (additional source)
Amphianthus inornata (Gravier, 1918) accepted as Stephanauge inornata (Gravier, 1918) (additional source)
Amphianthus islandicus Carlgren, 1942 (additional source)
Amphianthus margaritaceus (Danielssen, 1890) (additional source)
Amphianthus michaelsarsi Carlgren, 1934 (additional source)
Amphianthus mirabilis (Verrill, 1879) (additional source)
Amphianthus norvegicus Carlgren, 1942 (additional source)
Andresia parthenopea (Andrès, 1883) accepted as Andresia partenopea (Andrès, 1883) (additional source)
Andresiidae Stephenson, 1922 (additional source)
Anemonactis Andres, 1881 (additional source)
Anemonia Risso, 1827 (additional source)
Anemonia sulcata (Pennant, 1777) (additional source)
Antholoba Hertwig, 1882 (additional source)
Antholoba achates (Drayton in Dana, 1846) (additional source)
Antholoba perdix (Verrill, 1882) (additional source)
Anthopleura Duchassaing de Fonbressin & Michelotti, 1860 (additional source)
Anthopleura ballii (Cocks, 1851) (additional source)
Anthopleura crassa (Andrès, 1880) accepted as Cribrinopsis crassa (Andrès, 1881) (additional source)
Anthopleura thallia (Gosse, 1854) (additional source)
Anthosactis Danielssen, 1890 (additional source)
Anthosactis ingolfi Carlgren, 1921 (additional source)
Anthothoe Carlgren, 1938 (additional source)
Athenaria (additional source)
Aureliana accepted as Aureliania Gosse, 1860 (additional source)
Aureliana heterocera (Thompson, 1853) accepted as Capnea sanguinea Forbes, 1841 (additional source)
Bathyphellia Carlgren, 1932 (additional source)
Bathyphellia margaritacea (Danielssen, 1890) (additional source)
Bathyphelliidae Carlgren, 1932 (additional source)
Bolocera Gosse, 1860 (additional source)
Bolocera maxima Carlgren, 1921 (additional source)
Bolocera tuediae (Johnston, 1832) (additional source)
Boloceroidaria accepted as Boloceroididae Carlgren, 1924 (additional source)
Boloceroididae Carlgren, 1924 (additional source)
Bunodactis Verrill, 1899 (additional source)
Bunodactis biscayensis (Fischer, 1874) accepted as Bunodosoma biscayense (Fischer, 1874) accepted as Anthopleura biscayensis (Fischer, 1874) (additional source)
Bunodactis verrucosa (Pennant, 1777) (additional source)
Bunodeopsis Andres, 1881 (additional source)
Bunodeopsis strumosa Andrès, 1881 (additional source)
Bunodosoma Verrill, 1899 (additional source)
Cactosoma Danielssen, 1890 (additional source)
Cactosoma abyssorum Danielssen, 1890 (additional source)
Calliactis Verrill, 1869 (additional source)
Calliactis parasitica (Couch, 1842) (additional source)
Carlgrenia Stephenson, 1918 (additional source)
Carlgrenia desiderata Stephenson, 1918 (additional source)
Cataphellia Stephenson, 1929 (additional source)
Cataphellia brodricii (Gosse, 1859) (additional source)
Cereus pedunculatus (Pennant, 1777) (additional source)
Chondrophellia Carlgren, 1925 (additional source)
Chondrophellia coronata (Verrill, 1883) (additional source)
Condylactis Duchassaing de Fombressin & Michelotti, 1864 (additional source)
Condylactis aurantiaca (Delle Chiaje, 1825) (additional source)
Condylanthidae Stephenson, 1922 (additional source)
Corallimorpharia (additional source)
Corallimorphidae Hertwig, 1882 (additional source)
Corallimorphus Moseley, 1877 (additional source)
Corallimorphus atlanticus Carlgren, 1934 accepted as Corallimorphus rigidus Moseley, 1877 (additional source)
Corallimorphus ingens Gravier, 1918 (additional source)
Corallimorphus rigidus Moseley, 1877 (additional source)