• Alcyonium Linnaeus, 1758
• Alcyonium Pallas, 1766 accepted as Botryllus Gaertner, 1774
• Alcyonium (Erythropodium) accepted as Alcyonium Linnaeus, 1758
• Alcyonium (Erythropodium) contortum Kükenthal, 1906 accepted as Briareum hamrum (Gohar, 1948)
• Alcyonium (Erythropodium) indicum (Thomson & Henderson, 1905) accepted as Paraminabea indica (Thomson & Henderson, 1905)
• Alcyonium (Erythropodium) salomonense Thomson & Mackinnon, 1910 accepted as Erythropodium salomonense Thomson & Mackinnon, 1910
• Alcyonium (Metalcyonium) Pfeffer, 1889 accepted as Bellonella Gray, 1862
• Alcyonium (Metalcyonium) capitata (Pfeffer, 1889) accepted as Bellonella capitata (Pfeffer, 1889)
• Alcyonium (Metalcyonium) clavatum (Pfeffer, 1889) accepted as Bellonella clavata (Pfeffer, 1889)
• Alcyonium (Metalcyonium) novarae Kükenthal, 1906 accepted as Alcyonium novarae Kükenthal, 1906
• Alcyonium (Metalcyonium) patagonicum (May, 1899) accepted as Alcyonium patagonicum (May, 1899)
• Alcyonium acaule Marion, 1878
• Alcyonium adriaticum Kükenthal, 1907 accepted as Alcyonium palmatum Pallas, 1766
• Alcyonium agaricum Gmelin, 1791 accepted as Renilla reniformis (Pallas, 1766)
• Alcyonium agaricum Stimpson, 1855 accepted as Sarcophyton agaricum (Stimpson, 1855)
• Alcyonium alburnum Pallas, 1766 accepted as Telesto alburnum (Pallas, 1766)
• Alcyonium altum Tixier-Durivault, 1955 accepted as Nidaliopsis alta (Tixier-Durivault, 1955)
• Alcyonium amicorum Blainville accepted as Ammothea amicorum (Blainville)
• Alcyonium antarcticum Wright & Studer, 1889
• Alcyonium arboreum Linnaeus, 1758 accepted as Paragorgia arborea (Linnaeus, 1758)
• Alcyonium asbestinum Pallas, 1766 accepted as Briareum asbestinum (Pallas, 1766)
• Alcyonium ascidioides Pallas, 1774 accepted as Distomus variolosus Gaertner, 1774
• Alcyonium aspiculatum Tixier-Durivault, 1955
• Alcyonium aurantiacum Quoy & Gaimard, 1833 accepted as Kotatea aurantiaca (Quoy & Gaimard, 1833)
• Alcyonium aurantium Pallas, 1766 accepted as Tethya aurantium (Pallas, 1766)
• Alcyonium australe Macfadyen, 1936 accepted as Cladiella australis (Macfadyen, 1936)
• Alcyonium bocagei (Saville Kent, 1870)
• Alcyonium boletiforme Lamarck, 1815 accepted as Polymastia boletiformis (Lamarck, 1815)
• Alcyonium boletus Lamarck, 1815 accepted as Thorectandra boletus (Lamarck, 1815)
• Alcyonium borlasii Turton, 1807 accepted as Botryllus schlosseri (Pallas, 1766)
• Alcyonium bosphorense (Tixier-Durivault, 1961)
• Alcyonium brachyclados (Ehrenberg, 1834) accepted as Cladiella brachyclados (Ehrenberg, 1834)
• Alcyonium brachycladum (Ehrenberg, 1834) accepted as Alcyonium brachyclados (Ehrenberg, 1834) accepted as Cladiella brachyclados (Ehrenberg, 1834)
• Alcyonium bradleyi Verrill, 1869 (uncertain > nomen dubium)
• Alcyonium brioniense Kükenthal, 1907 accepted as Alcyonium acaule Marion, 1878
• Alcyonium bulbosum Esper, 1794 accepted as Suberites domuncula (Olivi, 1792)
• Alcyonium burmedju Sampaio, Stokvis & van Ofwegen, 2016
• Alcyonium bursa Linnaeus, 1758 accepted as Codium bursa (Olivi) C.Agardh, 1817
• Alcyonium caparti Tixier-Durivault, 1955 accepted as Complexum caparti (Tixier-Durivault, 1955)
• Alcyonium capitatum (Pfeffer, 1889) accepted as Bellonella capitata (Pfeffer, 1889)
• Alcyonium carneum Verrill, 1864 accepted as Gersemia rubiformis (Ehrenberg, 1834)
• Alcyonium catalai Tixier-Durivault, 1970
• Alcyonium ceicis Duchassaing & Michelotti, 1860 (uncertain)
• Alcyonium ceylonense May, 1899
• Alcyonium ceylonicum Pratt, 1905 accepted as Cladiella ceylonica (Pratt, 1905)
• Alcyonium cidaris Lamarck, 1815 accepted as Geodia cidaris (Lamarck, 1815)
• Alcyonium clavatum (Pfeffer, 1889) accepted as Bellonella clavata (Pfeffer, 1889)
• Alcyonium clavatum Studer, 1891
• Alcyonium compactofestucum Verseveldt & van Ofwegen, 1992
• Alcyonium compactum Lamarck, 1815 accepted as Suberites domuncula (Olivi, 1792)
• Alcyonium complanatum Verseveldt, 1977 accepted as Skamnarium complanatum (Verseveldt, 1977)
• Alcyonium compressum Studer, 1901
• Alcyonium confertum Dana, 1846 accepted as Sclerophytum confertum (Dana, 1846)
• Alcyonium conicum Olivi, 1792 accepted as Aplidium conicum (Olivi, 1792)
• Alcyonium contortum Kükenthal, 1906 accepted as Briareum hamrum (Gohar, 1948)
• Alcyonium coralloides (Pallas, 1766)
• Alcyonium cotoneum Pallas, 1766 accepted as Geodia cydonium (Linnaeus, 1767)
• Alcyonium cranium Müller, 1776 accepted as Craniella cranium (Müller, 1776)
• Alcyonium cuspidiferum Lamarck, 1815 accepted as Cervicornia cuspidifera (Lamarck, 1815)
• Alcyonium cydonium Linnaeus, 1767 accepted as Geodia cydonium (Linnaeus, 1767)
• Alcyonium cydonium Linnaeus, 1767 sensu Esper, 1829
• Alcyonium cylindricum Lamarck, 1815 accepted as Neopetrosia cylindrica (Lamarck, 1815)
• Alcyonium dendroides Thomson & Dean, 1931
• Alcyonium digitatum Linnaeus, 1758
• Alcyonium digitatum var. digitatum Molander, 1914
• Alcyonium digitatum var. norvegicum (Koren & Danielssen, 1883) accepted as Alcyonium norvegicum (Koren & Danielssen, 1883)
• Alcyonium digitulatum Klunzinger, 1877 accepted as Cladiella digitulata (Klunzinger, 1877)
• Alcyonium distinctum Williams, 1988 accepted as Porphyrophyton distinctum (Williams, 1988)
• Alcyonium distortum Lamarck, 1815 accepted as Petrosia (Petrosia) ficiformis (Poiret, 1789)
• Alcyonium dolium McFadden & van Ofwegen, 2017
• Alcyonium domuncula Olivi, 1792 accepted as Suberites domuncula (Olivi, 1792)
• Alcyonium echinatum Fleming, 1828 accepted as Hydractinia echinata (Fleming, 1828)
• Alcyonium echinatum Tixier-Durivault, 1970 accepted as Klyxum echinatum (Tixier-Durivault, 1970)
• Alcyonium elegans (Kükenthal, 1902)
• Alcyonium elegantissimum May, 1899 accepted as Lobularia elegantissima (May, 1899) accepted as Cladiella elegantissima (May, 1899)
• Alcyonium ensiferum Lamarck, 1815 accepted as Homaxinella ensifera (Lamarck, 1815)
• Alcyonium epipatium Linné accepted as Alcyonium epipetrum Linnaeus, 1767 accepted as Veretillum cynomorium (Pallas, 1766)
• Alcyonium epipetrum Linnaeus, 1767 accepted as Veretillum cynomorium (Pallas, 1766)
• Alcyonium epiphytum Lamarck, 1815 accepted as Protosuberites epiphytum (Lamarck, 1815)
• Alcyonium equisetiforme Lüttschwager, 1922 accepted as Klyxum equisetiforme (Lüttschwager, 1922)
• Alcyonium etheridgei Thomson & Mackinnon, 1911
• Alcyonium exos Leuckart (uncertain > unassessed)
• Alcyonium fallax Lüttschwager, 1922 accepted as Tenerodus fallax (Lüttschwager, 1922)
• Alcyonium faura J.S. Thomson, 1910 accepted as Alcyonium fauri J.S. Thomson, 1910
• Alcyonium fauri J.S. Thomson, 1910
• Alcyonium ficus Pallas, 1766 (uncertain > taxon inquirendum)
• Alcyonium ficus sensu Linnaeus, 1767 (uncertain > taxon inquirendum)
• Alcyonium flabellum Quoy & Gaimard, 1833 accepted as Paralemnalia flabella (Quoy & Gaimard, 1833)
• Alcyonium flaccidum Tixier-Durivault, 1966 accepted as Klyxum flaccidum (Tixier-Durivault, 1966)
• Alcyonium flaccidum aberrans Verseveldt, 1971 accepted as Klyxum flaccidum aberrans (Verseveldt, 1971)
• Alcyonium flavum Quoy & Gaimard, 1833 (uncertain)
• Alcyonium flexibile Quoy & Gaimard, 1833 accepted as Sclerophytum flexibile (Quoy & Gaimard, 1833)
• Alcyonium flexile Quoy & Gaimard, 1833 accepted as Sclerophytum flexibile (Quoy & Gaimard, 1833)
• Alcyonium floridum Esper, 1791 accepted as Spongodes florida (Esper, 1791) accepted as Dendronephthya florida (Esper, 1791)
• Alcyonium foliatum J. S. Thomson, 1921
• Alcyonium fruticosum Sars, 1860 accepted as Gersemia fruticosa (Sars, 1860)
• Alcyonium fulvum (Forskål, 1775) accepted as Rhytisma fulvum (Forskål, 1775)
• Alcyonium fulvum var. fulvum (uncertain > unassessed)
• Alcyonium fulvum var. sclera Cohn, 1908 accepted as Rhytisma fulvum (Forskål, 1775)
• Alcyonium fungiforme Tixier-Durivault, 1954 accepted as Alcyonium variabile (J.S. Thomson, 1921)