Acontiophoridae Carlgren, 1938 (additional source)
Acontiophorum (additional source)
Acontiophorum mortenseni Carlgren, 1938 (additional source)
Acraspedanthus Carlgren, 1924 (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 bocki Carlgren, 1943 (additional source)
Actinauge granulata Carlgren, 1928 (additional source)
Actinauge longicornis (Verrill, 1882) (additional source)
Actinauge richardi (Marion, 1906) (additional source)
Actinauge verrillii McMurrich, 1893 (additional source)
Actineria (additional source)
Actineria dendrophora Haddon & Shackleton, 1893 (additional source)
Actineria villosa Quoy & Gaimard in de Blainville, 1830 (additional source)
Actinernidae Stephenson, 1922 (additional source)
Actinernus Verrill, 1879 (additional source)
Actinernus antarcticus (Carlgren, 1914) (additional source)
Actinernus elongatus (Hertwig, 1882) (additional source)
Actinernus michaelsarsi Carlgren, 1918 (additional source)
Actinernus nobilis Verrill, 1879 (additional source)
Actinernus robustus (Hertwig, 1882) (additional source)
Actinia Pallas, 1766 accepted as Pentacta Goldfuss, 1820 (additional source)
Actinia bermudensis (McMurrich, 1889) (additional source)
Actinia cari Delle Chiaje, 1822 (additional source)
Actinia equina (Linnaeus, 1758) (additional source)
Actinia grobbeni Watzl, 1922 (additional source)
Actinia kraemeri Pax, 1914 (additional source)
Actinia tenebrosa Farquhar, 1898 (additional source)
Actiniaria (additional source)
Actiniidae Rafinesque, 1815 (additional source)
Actinodendron (additional source)
Actinodendron arboreum (Quoy & Gaimard, 1833) (additional source)
Actinodendron glomeratum Haddon, 1898 (additional source)
Actinodendron hansingorum Carlgren, 1900 (additional source)
Actinodendron plumosum Haddon, 1898 (additional source)
Actinoporus Duchassaing, 1850 (additional source)
Actinoporus elegans Duchassaing, 1850 (additional source)
Actinoporus elongatus Carlgren, 1900 (additional source)
Actinoscyphia Stephenson, 1920 (additional source)
Actinoscyphia aurelia (Stephenson, 1918) (additional source)
Actinoscyphia plebeia (McMurrich, 1893) (additional source)
Actinoscyphia saginata (Verrill, 1882) (additional source)
Actinoscyphia verrilli (Gravier, 1918) (additional source)
Actinostephanus Kwietniewski, 1897 (additional source)
Actinostephanus haeckeli Kwietniewski, 1897 (additional source)
Actinostola Verrill, 1883 (additional source)
Actinostola abyssorum (Danielssen, 1890) (additional source)
Actinostola callosa (Verrill, 1882) (additional source)
Actinostola carlgreni Wassilieff, 1908 (additional source)
Actinostola crassicornis (Hertwig, 1882) (additional source)
Actinostola georgiana Carlgren, 1927 (additional source)
Actinostola groenlandica Carlgren, 1899 (additional source)
Actinostola kerguelensis Carlgren, 1928 (additional source)
Actinostolidae Carlgren, 1932 (additional source)
Actinothoe Fischer, 1889 (additional source)
Actinothoe bradleyi (Verrill, 1869) (additional source)
Actinothoe carlgreni (Haddon & Duerden, 1896) (additional source)
Actinothoe georgiana (Carlgren, 1899) (additional source)
Actinothoe gracillima (McMurrich, 1887) (additional source)
Actinothoe gravieri (Pax, 1912) (additional source)
Actinothoe ignea (Fischer, 1874) (additional source)
Actinothoe kerguelensis (Pax, 1922) (additional source)
Actinothoe lobata (Carlgren, 1899) (additional source)
Actinothoe milmani (Haddon & Shackleton, 1893) (additional source)
Actinothoe modesta (Verrill, 1866) (additional source)
Actinothoe paradoxa (McMurrich, 1893) (additional source)
Actinothoe patagonica (Carlgren, 1899) (additional source)
Actinothoe plebeia (Haddon, 1898) (additional source)
Actinothoe pustulata (McMurrich, 1887) (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)
Aiptasia insignis Carlgren, 1941 (additional source)
Aiptasiidae Carlgren, 1924 (additional source)
Aiptasiomorpha Stephenson, 1920 (additional source)
Aiptasiomorpha elongata Carlgren, 1951 (additional source)
Aiptasiomorpha minima (Stephenson, 1918) (additional source)
Aiptasiomorpha paxi Stephenson, 1920 (additional source)
Aiptasiomorphidae Carlgren, 1949 (original description)
Alicia beebei Carlgren, 1940 (additional source)
Alicia mirabilis Johnson, 1861 (additional source)
Alicia pretiosa (Dana, 1846) (additional source)
Alicia rhadina Haddon & Shackleton, 1893 (additional source)
Alicia sansibarensis Carlgren, 1900 (additional source)
Alicia uruguayensis Carlgren, 1927 (additional source)
Aliciidae Duerden, 1895 (additional source)
Allantactis Danielssen, 1890 (additional source)
Allantactis parasitica Danielssen, 1890 (additional source)
Amphianthus armatus Carlgren, 1928 (additional source)
Amphianthus bathybium Hertwig, 1882 (additional source)
Amphianthus brunneus (Pax, 1909) (additional source)
Amphianthus californicus Carlgren, 1936 (additional source)
Amphianthus capensis Carlgren, 1928 (additional source)
Amphianthus ingolfi Carlgren, 1942 (additional source)
Amphianthus islandicus Carlgren, 1942 (additional source)