• Aglaothamnion bipinnatum (P.L. Crouan & H.M. Crouan) Feldmann & G. Feldmann, 1948
• Aglaothamnion bipinnatum (P.L. Crouan & H.M. Crouan) Feldmann-Mazoyer, 1941
• Aglaothamnion boergesenii (Aponte & D.L. Ballantine) L'Hardy-Halos & Rueness, 1997
• Aglaothamnion brodiei (Harvey) Feldmann-Mazoyer, 1941 accepted as Aglaothamnion hookeri (Dillwyn) Maggs & Hommersand, 1993
• Aglaothamnion byssoides (Arnott ex Harvey) C.F. Boudouresque & M.M. Perret-Boudouresque, 1987 accepted as Aglaothamnion tenuissimum (Bonnemaison) Feldmann-Mazoyer, 1941
• Aglaothamnion callophyllidicola (Yamada) Boo, I.K. Lee, Rueness & Yoshida, 1991
• Aglaothamnion caudatum (J.G. Agardh) Feldmann-Mazoyer, 1941
• Aglaothamnion chadefaudii L'Hardy-Halos, 1984
• Aglaothamnion chejuense G.H. Kim & I.K. Lee
• Aglaothamnion collinsii Aponte, D.L. Ballantine & J.N. Norris, 1997
• Aglaothamnion cordatum (Børgesen) Feldmann-Mazoyer, 1941
• Aglaothamnion decompositum (J.G. Agardh) Halos
• Aglaothamnion diaphanum L'Hardy-Halos & Maggs, 1991
• Aglaothamnion endovagum (Setchell & N.L. Gardner) I.A. Abbott, 1972
• Aglaothamnion fasciculatum (Harvey) Maggs & L'Hardy-Halos, 1993
• Aglaothamnion feldmanniae Halos, 1965
• Aglaothamnion felipponei (Howe) Aponte, Ballantine & J.N. Norris, 1994
• Aglaothamnion felliponei (M.A. Howe) Aponte, D.L. Ballantine & J.N. Norris, 1994
• Aglaothamnion flexibile N.E. Aponte & D.L. Ballantine, 1995
• Aglaothamnion furcellariae (J.G. Agardh) Feldmann-Mazoyer, 1941 accepted as Aglaothamnion tenuissimum (Bonnemaison) Feldmann-Mazoyer, 1941
• Aglaothamnion gaillonii (P.L. Crouan & H.M. Crouan) Halos, 1965
• Aglaothamnion gallicum (Nägeli) Halos ex Ardré, 1970
• Aglaothamnion halliae (F.S. Collins) N.E. Aponte, D.L. Ballantine & J.N. Norris, 1997
• Aglaothamnion herveyi (M.A. Howe) N.E. Aponte, D.L. Ballantine & J.N. Norris, 1994
• Aglaothamnion hookeri (Dillwyn) Maggs & Hommersand, 1993
• Aglaothamnion monopodon Børgesen, 1945
• Aglaothamnion neglectum Feldmann-Mazoyer, 1941 accepted as Aglaothamnion cordatum (Børgesen) Feldmann-Mazoyer, 1941
• Aglaothamnion obstipum Cowling, Kraft & J.A. West, 1998
• Aglaothamnion okiense Kajimura, 1994
• Aglaothamnion oosumiense Itono, 1971
• Aglaothamnion polyspermum (C. Agardh) Parke, 1953 accepted as Aglaothamnion hookeri (Dillwyn) Maggs & Hommersand, 1993
• Aglaothamnion priceanum Maggs, Guiry & Rueness, 1991
• Aglaothamnion pseudobyssoides (P.L. Crouan & H.M. Crouan) Halos, 1965
• Aglaothamnion rabenhorstii (Kützing) L'Hardy-Halos
• Aglaothamnion rigidulum De Clerck, Bolton, R.J. Anderson & Coppejans, 2004 accepted as Heteroptilon rigidulum (De Clerck, Bolton, R.J. Anderson & Coppejans) Hommersand & De Clerck, 2006
• Aglaothamnion roseum (Roth) Maggs & L'Hardy-Halos, 1993
• Aglaothamnion sarcodiae Børgesen, 1952
• Aglaothamnion scopulorum (C. Agardh) Feldmann-Mazoyer, 1941 accepted as Aglaothamnion hookeri (Dillwyn) Maggs & Hommersand, 1993
• Aglaothamnion sepositum (Gunnerus) Maggs & Hommersand, 1993
• Aglaothamnion tenuissimum (Bonnemaison) Feldmann-Mazoyer, 1941
• Aglaothamnion tripinnatum (C. Agardh) Feldmann-Mazoyer, 1941
• Aglaothamnion uruguayense (W.R. Taylor) N.E. Aponte, D.L. Ballantine & J.N. Norris, 1994
• Aglaothamnion westbrookiae Rueness & L'Hardy-Halos, 1991 accepted as Aglaothamnion halliae (F.S. Collins) N.E. Aponte, D.L. Ballantine & J.N. Norris, 1997
• Aristoptilon mooreanum (Lindauer) Hommersand & W.A. Nelson, 2006
• Aristothamnion callithamnioides A.B. Joly & Ugadim, 1966
• Aristothamnion collabens (Rudolphi) Papenfuss, 1968 accepted as Callithamnion collabens (Rudolphi) L. McIvor & Maggs, 2002
• Aristothamnion purpuriferum (Kützing) J.G. Agardh, 1892 accepted as Callithamnion collabens (Rudolphi) L. McIvor & Maggs, 2002
• Aristothamnion ramelliferum Baardseth, 1941
• Aristothamnion tysonii
• Callithamnion abbreviatum Kützing, 1843 accepted as Herpothamnion abbreviatum (Kützing) Nägeli, 1862
• Callithamnion abietinum Reinsch, 1875 accepted as Pterothamnion crispum (Ducluzeau) Nägeli, 1862
• Callithamnion acanthophorum Kützing, 1849 accepted as Macrothamnion acanthophorum (Kützing)Womersley, 1998
• Callithamnion acrospermum J.G. Agardh, 1851
• Callithamnion aculeatum Harvey, 1855 accepted as Trithamnion aculeatum (Harvey) Womersley & Wollaston, 1998
• Callithamnion acuminatum Schousboe
• Callithamnion acutum Kylin, 1925
• Callithamnion adnatum J.G. Agardh, 1879 accepted as Antithamnionella adnata (J.G. Agardh) N.M. Adams, 1991
• Callithamnion aegagrophila Funk, 1922 accepted as Callithamniella tingitana (Schousboe ex Bornet) Feldmann-Mazoyer, 1938
• Callithamnion aegagropilum J.G. Agardh, 1876 accepted as Lejolisia aegagropila (J.G. Agardh) J.G. Agardh, 1892
• Callithamnion affine Harvey, 1833 accepted as Callithamnion tetragonum (Withering) S.F. Gray, 1821
• Callithamnion affine Kützing, 1843 accepted as Acrochaetium savianum (Meneghini) Nägeli, 1862
• Callithamnion agardhianum Trevisan
• Callithamnion aglaothamniodes Itono, 1971
• Callithamnion alternatum Schousboe
• Callithamnion amentaceum P.L. Crouan & H.M. Crouan
• Callithamnion americanum Harvey, 1853 accepted as Scagelia americana (Harvey) Athanasiadis, 1996
• Callithamnion angustatum J.D. Hooker & Harvey, 1847 accepted as Hirsutithallia angustata (J.D. Hooker & Harvey) Wollaston & Womersley, 1998
• Callithamnion apicale Noda, 1973 accepted as Aglaothamnion callophyllidicola (Yamada) Boo, I.K. Lee, Rueness & Yoshida, 1991
• Callithamnion apiculatum Meneghini, 1844
• Callithamnion apiculatum P.L. Crouan & H.M. Crouan, 1878
• Callithamnion applicitum Harvey, 1855 accepted as Antithamnion pectinatum (Montagne) J. Brauner, 1994
• Callithamnion arachnoideum C. Agardh, 1828 accepted as Aglaothamnion tenuissimum (Bonnemaison) Feldmann-Mazoyer, 1941
• Callithamnion arachnoideum Griffiths ex Moore, 1837
• Callithamnion arborescens N.L. Gardner, 1927
• Callithamnion arbuscula (Dillwyn) Lyngbye, 1819 accepted as Aglaothamnion sepositum (Gunnerus) Maggs & Hommersand, 1993
• Callithamnion armatum J.G. Agardh, 1885 accepted as Antithamnion armatum (J.G. Agardh) De Toni, 1903
• Callithamnion arnottii Trevisan, 1845 accepted as Aglaothamnion tenuissimum (Bonnemaison) Feldmann-Mazoyer, 1941
• Callithamnion arrawaricum A.J.K. Millar, 1990
• Callithamnion australe J.G. Agardh, 1841 accepted as Shepleya australis (J.G. Agardh) E.M. Gordon, 1972
• Callithamnion axillare Schousboe
• Callithamnion axirhizans Reinsch
• Callithamnion baccatum J.G. Agardh, 1870 accepted as Vickersia baccata (J.G. Agardh) Karsakoff, 1896
• Callithamnion baileyi Harvey, 1853
• Callithamnion ballioides Sonder, 1853 accepted as Inkyuleea ballioides (Sonder) H.-G. Choi, Kraft & G.W. Saunders, 2000
• Callithamnion barbatum C. Agardh, 1828 accepted as Ptilothamnion pluma (Dillwyn) Thuret, 1863
• Callithamnion batrachospermum Kützing
• Callithamnion beauii P.L. Crouan & H.M. Crouan, 1865 accepted as Wrangelia argus (Montagne) Montagne, 1856
• Callithamnion bebbii Reinsch, 1875 accepted as Pterothamnion crispum (Ducluzeau) Nägeli, 1862
• Callithamnion bipinnatum P.L. Crouan & H.M. Crouan, 1867 accepted as Aglaothamnion bipinnatum (P.L. Crouan & H.M. Crouan) Feldmann-Mazoyer, 1941
• Callithamnion biseriatum Kylin, 1925
• Callithamnion bisporum N.L. Gardner, 1927
• Callithamnion boergesenii Aponte & Ballantine, 1990 accepted as Aglaothamnion boergesenii (Aponte & D.L. Ballantine) L'Hardy-Halos & Rueness, 1997
• Callithamnion borreri (J.E. Smith) C. Agardh, 1828 accepted as Pleonosporium borreri (J.E. Smith) Nägeli, 1862
• Callithamnion botryocarpum Harvey, 1855 accepted as Colaconema caespitosum (J.G. Agardh) Jackelman, Stegenga & J.J. Bolton, 1991
• Callithamnion brachiatum (Bonnemaison) Harvey, 1847 accepted as Callithamnion tetragonum (Withering) S.F. Gray, 1821
• Callithamnion brachygonum Harvey, 1855
• Callithamnion breviramosum Gardner, 1927 accepted as Callithamnion rupinicola C.L. Anderson, 1894
• Callithamnion brodiei Harvey, 1833 accepted as Aglaothamnion hookeri (Dillwyn) Maggs & Hommersand, 1993
• Callithamnion brownianum Harvey, 1855 accepted as Spongoclonium brownianum (Harvey) J.G. Agardh, 1892
• Callithamnion byssaceum Kützing, 1843 accepted as Acrochaetium secundatum (Lyngbye) Nägeli, 1858