• Acanthascus (Acanthascus) alani Ijima, 1898
• Acanthascus (Acanthascus) alani alani Ijima, 1898
• Acanthascus (Acanthascus) alani microdiscoctasterus Tabachnick, Menshenina & Ehrlich, 2023
• Acanthascus (Acanthascus) cactus Schulze, 1886
• Acanthascus (Acanthascus) koltuni Reiswig & Stone, 2013
• Acanthascus (Acanthascus) malacus Reiswig, 2014
• Acanthascus (Acanthascus) pachyderma Okada, 1932
• Acanthascus (Acanthascus) platei Schulze, 1899
• Acanthascus (Acanthascus) profundus Koltun, 1967
• Acanthascus (Acanthascus) sacculus Ferrer Hernández, 1932
• Acanthascus (Rhabdocalyptus) arcticus (Brøndsted, 1916)
• Acanthascus (Rhabdocalyptus) asper (Schulze, 1899)
• Acanthascus (Rhabdocalyptus) australis (Topsent, 1901)
• Acanthascus (Rhabdocalyptus) baculifer (Schulze, 1904)
• Acanthascus (Rhabdocalyptus) bidentatus (Okada, 1932)
• Acanthascus (Rhabdocalyptus) borealis (Okada, 1932)
• Acanthascus (Rhabdocalyptus) capillatus (Ijima, 1897)
• Acanthascus (Rhabdocalyptus) dawsoni (Lambe, 1893)
• Acanthascus (Rhabdocalyptus) gomezi (Tabachnick & Fromont, 2019)
• Acanthascus (Rhabdocalyptus) heteraster (Okada, 1932)
• Acanthascus (Rhabdocalyptus) lophodigitatus (Kirkpatrick, 1901)
• Acanthascus (Rhabdocalyptus) mirabilis (Schulze, 1899)
• Acanthascus (Rhabdocalyptus) mollis (Schulze, 1886)
• Acanthascus (Rhabdocalyptus) monstraster (Tabachnick, 1994)
• Acanthascus (Rhabdocalyptus) nodulosus (Schulze, 1899)
• Acanthascus (Rhabdocalyptus) plumodigitatus (Kirkpatrick, 1902) accepted as Acanthascus (Rhabdocalyptus) lophodigitatus (Kirkpatrick, 1901)
• Acanthascus (Rhabdocalyptus) tener (Schulze, 1899)
• Acanthascus (Rhabdocalyptus) tenuis (Schulze, 1899)
• Acanthascus (Rhabdocalyptus) trichotis (Reiswig, 2018)
• Acanthascus (Rhabdocalyptus) unguiculatus (Ijima, 1904)
• Acanthascus (Rhabdocalyptus) victor (Ijima, 1897)
• Acanthascus (Staurocalyptus) affinis (Ijima, 1904)
• Acanthascus (Staurocalyptus) celebesianus (Ijima, 1927)
• Acanthascus (Staurocalyptus) dowlingi (Lambe, 1893)
• Acanthascus (Staurocalyptus) entacanthus (Ijima, 1904)
• Acanthascus (Staurocalyptus) fasciculatus (Schulze, 1899)
• Acanthascus (Staurocalyptus) fuca (Tabachnick, 1989)
• Acanthascus (Staurocalyptus) glaber (Ijima, 1897)
• Acanthascus (Staurocalyptus) hamatus (Lendenfeld, 1915)
• Acanthascus (Staurocalyptus) heteractinus (Ijima, 1897)
• Acanthascus (Staurocalyptus) microchetus (Ijima, 1898)
• Acanthascus (Staurocalyptus) pamelaturnerae (Reiswig, 2018)
• Acanthascus (Staurocalyptus) pleorhaphides (Ijima, 1897)
• Acanthascus (Staurocalyptus) psilosus (Reiswig & Stone, 2013)
• Acanthascus (Staurocalyptus) roeperi (Schulze, 1886)
• Acanthascus (Staurocalyptus) rugocruciatus (Okada, 1932)
• Acanthascus (Staurocalyptus) solidus (Schulze, 1899)
• Acanthascus (Staurocalyptus) tubulosus (Ijima, 1904)
• Acanthascus (Staurocalyptus) tylotus (Reiswig & Stone, 2013)
• Acanthascus affinis (Ijima, 1904) accepted as Staurocalyptus affinis Ijima, 1904 represented as Acanthascus (Staurocalyptus) affinis (Ijima, 1904)
• Acanthascus alani Ijima, 1898 represented as Acanthascus (Acanthascus) alani Ijima, 1898
• Acanthascus alani profundum Koltun, 1967 accepted as Acanthascus (Acanthascus) profundus Koltun, 1967
• Acanthascus arcticus (Brøndsted, 1916) accepted as Acanthascus (Rhabdocalyptus) arcticus (Brøndsted, 1916)
• Acanthascus asper (Schulze, 1899) accepted as Rhabdocalyptus asper Schulze, 1899 represented as Acanthascus (Rhabdocalyptus) asper (Schulze, 1899)
• Acanthascus australis (Topsent, 1901) accepted as Rhabdocalyptus australis Topsent, 1901 represented as Acanthascus (Rhabdocalyptus) australis (Topsent, 1901)
• Acanthascus baculifer (Schulze, 1904) accepted as Rhabdocalyptus baculifer Schulze, 1904 represented as Acanthascus (Rhabdocalyptus) baculifer (Schulze, 1904)
• Acanthascus bidentatus (Okada, 1932) accepted as Rhabdocalyptus bidentatus Okada, 1932 represented as Acanthascus (Rhabdocalyptus) bidentatus (Okada, 1932)
• Acanthascus borealis (Okada, 1932) accepted as Rhabdocalyptus borealis Okada, 1932 represented as Acanthascus (Rhabdocalyptus) borealis (Okada, 1932)
• Acanthascus cactus Schulze, 1886 represented as Acanthascus (Acanthascus) cactus Schulze, 1886
• Acanthascus capillatus (Ijima, 1897) accepted as Rhabdocalyptus capillatus Ijima, 1897 represented as Acanthascus (Rhabdocalyptus) capillatus (Ijima, 1897)
• Acanthascus celebesianus (Ijima, 1927) accepted as Staurocalyptus celebesianus Ijima, 1927 represented as Acanthascus (Staurocalyptus) celebesianus (Ijima, 1927)
• Acanthascus dawsoni (Lambe, 1893) accepted as Rhabdocalyptus dawsoni (Lambe, 1893) represented as Acanthascus (Rhabdocalyptus) dawsoni (Lambe, 1893)
• Acanthascus dowlingi (Lambe, 1893) accepted as Staurocalyptus dowlingi (Lambe, 1893) represented as Acanthascus (Staurocalyptus) dowlingi (Lambe, 1893)
• Acanthascus dubius Schulze, 1886 accepted as Rossella dubia (Schulze, 1886)
• Acanthascus entacanthus (Ijima, 1904) accepted as Staurocalyptus entacanthus Ijima, 1904 represented as Acanthascus (Staurocalyptus) entacanthus (Ijima, 1904)
• Acanthascus fasciculatus (Schulze, 1899) accepted as Staurocalyptus fasciculatus Schulze, 1899 represented as Acanthascus (Staurocalyptus) fasciculatus (Schulze, 1899)
• Acanthascus fuca (Tabachnick, 1989) accepted as Staurocalyptus fuca Tabachnick, 1989 represented as Acanthascus (Staurocalyptus) fuca (Tabachnick, 1989)
• Acanthascus glaber (Ijima, 1897) accepted as Staurocalyptus glaber Ijima, 1897 represented as Acanthascus (Staurocalyptus) glaber (Ijima, 1897)
• Acanthascus grossularia Schulze, 1886 accepted as Rossella antarctica Carter, 1872
• Acanthascus hamatus (Lendenfeld, 1915) accepted as Staurocalyptus hamatus Lendenfeld, 1915 represented as Acanthascus (Staurocalyptus) hamatus (Lendenfeld, 1915)
• Acanthascus heteractinus (Ijima, 1897) accepted as Staurocalyptus heteractinus Ijima, 1897 represented as Acanthascus (Staurocalyptus) heteractinus (Ijima, 1897)
• Acanthascus heteraster (Okada, 1932) accepted as Rhabdocalyptus heteraster Okada, 1932 represented as Acanthascus (Rhabdocalyptus) heteraster (Okada, 1932)
• Acanthascus koltuni Reiswig & Stone, 2013 represented as Acanthascus (Acanthascus) koltuni Reiswig & Stone, 2013
• Acanthascus malacus Reiswig, 2014 represented as Acanthascus (Acanthascus) malacus Reiswig, 2014
• Acanthascus microchetus (Ijima, 1898) accepted as Staurocalyptus microchetus Ijima, 1898 represented as Acanthascus (Staurocalyptus) microchetus (Ijima, 1898)
• Acanthascus mirabilis (Schulze, 1899) accepted as Rhabdocalyptus mirabilis Schulze, 1899 represented as Acanthascus (Rhabdocalyptus) mirabilis (Schulze, 1899)
• Acanthascus mollis (Schulze, 1886) accepted as Acanthascus (Rhabdocalyptus) mollis (Schulze, 1886)
• Acanthascus monstraster (Tabachnick, 1994) accepted as Rhabdocalyptus monstraster Tabachnick, 1994 represented as Acanthascus (Rhabdocalyptus) monstraster (Tabachnick, 1994)
• Acanthascus nealus de Laubenfels, 1942 accepted as Schaudinnia rosea (Fristedt, 1887)
• Acanthascus nodulosus (Schulze, 1899) accepted as Rhabdocalyptus nodulosus Schulze, 1899 represented as Acanthascus (Rhabdocalyptus) nodulosus (Schulze, 1899)
• Acanthascus pachyderma Okada, 1932 represented as Acanthascus (Acanthascus) pachyderma Okada, 1932
• Acanthascus platei Schulze, 1899 represented as Acanthascus (Acanthascus) platei Schulze, 1899
• Acanthascus pleorhaphides (Ijima, 1897) accepted as Staurocalyptus pleorhaphides Ijima, 1897 represented as Acanthascus (Staurocalyptus) pleorhaphides (Ijima, 1897)
• Acanthascus plumodigitatus (Kirkpatrick, 1901) accepted as Rhabdocalyptus plumodigitatus Kirkpatrick, 1902 accepted as Rhabdocalyptus lophodigitatus Kirkpatrick, 1901 represented as Acanthascus (Rhabdocalyptus) lophodigitatus (Kirkpatrick, 1901)
• Acanthascus profundum Koltun, 1967 accepted as Acanthascus profundus Koltun, 1967 represented as Acanthascus (Acanthascus) profundus Koltun, 1967
• Acanthascus profundus Koltun, 1967 represented as Acanthascus (Acanthascus) profundus Koltun, 1967
• Acanthascus roeperi (Schulze, 1886) accepted as Staurocalyptus roeperi (Schulze, 1886) represented as Acanthascus (Staurocalyptus) roeperi (Schulze, 1886)
• Acanthascus rugocruciatus (Okada, 1932) accepted as Staurocalyptus rugocruciatus Okada, 1932 represented as Acanthascus (Staurocalyptus) rugocruciatus (Okada, 1932)
• Acanthascus sacculus Ferrer Hernández, 1932 represented as Acanthascus (Acanthascus) sacculus Ferrer Hernández, 1932
• Acanthascus solidus (Schulze, 1899) accepted as Staurocalyptus solidus Schulze, 1899 represented as Acanthascus (Staurocalyptus) solidus (Schulze, 1899)
• Acanthascus tener (Schulze, 1899) accepted as Rhabdocalyptus tener Schulze, 1899 represented as Acanthascus (Rhabdocalyptus) tener (Schulze, 1899)
• Acanthascus tenuis (Schulze, 1899) accepted as Rhabdocalyptus tenuis (Schulze, 1899) represented as Acanthascus (Rhabdocalyptus) tenuis (Schulze, 1899)
• Acanthascus tubulosus (Ijima, 1904) accepted as Staurocalyptus tubulosus Ijima, 1904 represented as Acanthascus (Staurocalyptus) tubulosus (Ijima, 1904)
• Acanthascus unguiculatus (Ijima, 1904) accepted as Rhabdocalyptus unguiculatus Ijima, 1904 represented as Acanthascus (Rhabdocalyptus) unguiculatus (Ijima, 1904)
• Acanthascus victor (Ijima, 1897) accepted as Rhabdocalyptus victor Ijima, 1897 represented as Acanthascus (Rhabdocalyptus) victor (Ijima, 1897)
• Acanthosaccus tenuis Schulze, 1899 accepted as Acanthascus (Rhabdocalyptus) tenuis (Schulze, 1899)
• Acoelocalyx brucei Topsent, 1910
• Advhena magnifica Castello-Branco, Collins & Hajdu, 2020
• Alcyoncellum corbicula Bowerbank, 1862 accepted as Heterotella corbicula (Bowerbank, 1862)
• Alcyoncellum gelatinosum Blainville, 1834 accepted as Sycon gelatinosum (Blainville, 1834)