Acanthophora J.V.Lamouroux, 1813 (basis of record)
Acanthophora muscoides (Linnaeus) Bory de Saint-Vincent, 1828 (basis of record)
Acanthophora nayadiformis (Delile) Papenfuss, 1968 (additional source)
Acetabularia J.V.Lamouroux, 1812 (basis of record)
Acinetospora Bornet, 1891 (basis of record)
Acinetospora crinita (Carmichael) Sauvageau, 1899 (basis of record)
Acrochaete N.Pringsheim, 1862 accepted as Ulvella P.L.Crouan & H.M.Crouan, 1859 (basis of record)
Acrochaete cladophorae (Hornby) R.Nielsen, 1995 accepted as Ulvella cladophorae (Hornby) A.C.Mathieson & Dawes, 2017 (basis of record)
Acrochaete geniculata (N.L.Gardner) O'Kelly, 1983 accepted as Ulvella geniculata (N.L.Gardner) R.Nielsen, C.J.O'Kelly & B. Wysor, 2013 (basis of record)
Acrochaetiaceae Melchior, 1954 (basis of record)
Acrochaetiales (basis of record)
Acrochaetium Nägeli, 1858 (basis of record)
Acrochaetium alariae (Jónsson) Bornet, 1904 (basis of record)
Acrochaetium balticum (Rosenvinge) Aleem & Schulz, 1952 (basis of record)
Acrochaetium barbadensis (Vickers) Borgesen, 1915 (basis of record)
Acrochaetium battersianum Hamel, 1927 (basis of record)
Acrochaetium boergesenii Schiffner, 1931 (basis of record)
Acrochaetium brebneri (Batters) Hamel, 1928 (basis of record)
Acrochaetium canariense Børgesen, 1927 (basis of record)
Acrochaetium catenulatum M.Howe, 1914 (basis of record)
Acrochaetium cheminii Feldmann, 1954 (basis of record)
Acrochaetium corymbiferum (Thuret) Batters, 1902 accepted as Colaconema corymbiferum (Thuret) Alongi, Cormaci & G.Furnari, 2017 (basis of record)
Acrochaetium cymopoliae Børgesen, 1927 (basis of record)
Acrochaetium cytophagum (Rosenvinge) Hamel, 1927 (basis of record)
Acrochaetium densum (K.M.Drew) Papenfuss, 1945 accepted as Acrochaetium catenulatum M.Howe, 1914 (basis of record)
Acrochaetium duboscqii Feldmann, 1935 (basis of record)
Acrochaetium dumontiae (Rosenvinge) Hamel, 1927 (basis of record)
Acrochaetium emergens (Rosenvinge) Weber Bosse, 1921 accepted as Colaconema emergens (Rosenvinge) R.Nielsen, 1994 (basis of record)
Acrochaetium endozoicum (Darbishire) Batters, 1902 (basis of record)
Acrochaetium extensum Ercegovic, 1957 (basis of record)
Acrochaetium gynandrum (Rosenvinge) Hamel, 1927 accepted as Colaconema gynandrum (Rosenvinge) R.Nielsen, 1994 (basis of record)
Acrochaetium hauckii Schiffner, 1916 (basis of record)
Acrochaetium humile (Rosenvinge) Børgesen, 1915 (basis of record)
Acrochaetium immersum (Rosenvinge) Hamel, 1927 (basis of record)
Acrochaetium inclusum (Levring) Papenfuss, 1945 (basis of record)
Acrochaetium incrassatum Ercegovic, 1957 (basis of record)
Acrochaetium kylinii Hamel, 1927 (basis of record)
Acrochaetium lenormandii (Suhr ex Kützing) Nägeli, 1862 accepted as Acrochaetium secundatum (Lyngbye) Nägeli, 1858 (basis of record)
Acrochaetium leptonema (Rosenvinge) Børgesen, 1915 accepted as Colaconema leptonema (Rosenvinge) Alongi, Cormaci & G.Furnari, 2017 (basis of record)
Acrochaetium liagorae Børgesen, 1915 (basis of record)
Acrochaetium lorrain-smithiae (Lyle) L.Newton, 1931 (basis of record)
Acrochaetium macula (Rosenvinge) Hamel, 1927 (basis of record)
Acrochaetium mediterraneum (Levring) Athanasiadis, 2003 (basis of record)
Acrochaetium microfilum C.-C.Jao, 1936 (basis of record)
Acrochaetium microscopicum (Nägeli ex Kützing) Nägeli, 1858 (basis of record)
Acrochaetium minutissimum (Shur) Nägeli, 1861 accepted as Acrochaetium minutissimum Nägeli, 1862 accepted as Acrochaetium minutum (Suhr) Hamel, 1927 (basis of record)
Acrochaetium minutum (Suhr) Hamel, 1927 (basis of record)
Acrochaetium mirabilis (Suhr) Nägeli, 1862 (basis of record)
Acrochaetium molinieri Coppejans & Boudouresque, 1976 (basis of record)
Acrochaetium moniliforme (Rosenvinge) Børgesen, 1915 (basis of record)
Acrochaetium nitophyllii (Levring) Papenfuss, 1945 (basis of record)
Acrochaetium pallens (Zanardini) Nägeli, 1862 (basis of record)
Acrochaetium parvulum (Kylin) Hoyt, 1920 (basis of record)
Acrochaetium pulchellum Børgesen, 1915 (basis of record)
Acrochaetium radiatum C.-C.Jao, 1936 accepted as Acrochaetium humile (Rosenvinge) Børgesen, 1915 (basis of record)
Acrochaetium reductum (Rosenvinge) Hamel, 1927 (basis of record)
Acrochaetium robustum Børgesen, 1915 accepted as Colaconema robustum (Børgesen) Huisman & Woelkerling, 2018 (basis of record)
Acrochaetium rosulata (Rosenvinge) Papenfuss accepted as Acrochaetium rosulatum (Rosenvinge) Papenfuss, 1945 accepted as Kylinia rosulata Rosenvinge, 1909 (basis of record)
Acrochaetium sanctae-mariae (Darbishire) Hamel, 1927 (basis of record)
Acrochaetium savianum (Meneghini) Nägeli, 1862 accepted as Colaconema savianum (Meneghini) R.Nielsen, 1994 (basis of record)
Acrochaetium secundatum (Lyngbye) Nägeli, 1858 (basis of record)
Acrochaetium seiriolanum (Gibson) Rosenvinge, 1924 accepted as Acrochaetium seiriolanum (Harvey-Gibson) Hamel, 1927 (basis of record)
Acrochaetium sparsum (Harvey) Nägeli, 1862 (basis of record)
Acrochaetium stilophorae (Levring) Kylin, 1944 (basis of record)
Acrochaetium subpinnatum Bornet ex Hamel, 1927 (basis of record)
Acrochaetium subseriatum Børgesen, 1932 (basis of record)
Acrochaetium subtilissimum (Kützing) Hamel, 1927 accepted as Colaconema subtilissimum (Kützing) Alongi, Cormaci & G.Furnari, 2017 (basis of record)
Acrochaetium unifilum C.-C.Jao, 1936 (basis of record)
Acrochaetium virgatulum (Harvey) Batters, 1902 accepted as Acrochaetium secundatum (Lyngbye) Nägeli, 1858 (basis of record)
Acrocytis Rosenvinge, 1933 (basis of record)
Acrocytis groenlandica Rosenvinge (basis of record)
Acrodiscus Zanardini, 1869 (basis of record)
Acrodiscus vidovichii (Meneghini) Zanardini, 1868 (basis of record)
Acrosiphonia J.Agardh, 1846 (basis of record)
Acrosiphonia arcta (Dillwyn) Gain, 1912 (basis of record)
Acrosiphonia arctiuscula (Kützing) Jónsson accepted as Acrosiphonia arcta (Dillwyn) Gain, 1912 (basis of record)
Acrosiphonia flagellata Kjellman, 1893 (basis of record)
Acrosiphonia grandis Kjelmann, 1893 (basis of record)
Acrosiphonia incurva Kjellman, 1893 (basis of record)
Acrosiphonia sonderi (Kützing) Kornmann, 1962 (basis of record)
Acrosiphonia spinescens (Kützing) Kjellman, 1893 (basis of record)
Acrosiphoniaceae S. Jónsson, 1959 (additional source)
Acrosorium Zanardini ex Kützing, 1869 (basis of record)
Acrosorium venulosum (Zanardini) Kylin, 1924 (basis of record)
Acrospongium Schiffner, 1916 (basis of record)
Acrospongium ralfsioides Schiffner, 1916 (basis of record)
Acrosymphytaceae S.C.Lindstrom, 1987 (basis of record)
Acrosymphyton Sjöstedt, 1926 (basis of record)
Acrosymphyton purpuriferum (J.Agardh) G.Sjöstedt, 1926 (basis of record)
Acrosymphyton taylorii I.A.Abbott, 1962 (basis of record)
Acrothamnion J.Agardh, 1892 (basis of record)
Acrothamnion preissii (Sonder) E.M.Wollaston, 1968 (additional source)
Acrothrix Kylin, 1907 (basis of record)
Acrothrix gracilis Kylin, 1907 (basis of record)
Adriogloia Ercegovic, 1955 (basis of record)
Adriogloia adriatica Ercegovic, 1955 (basis of record)
Aeodes J.Agardh, 1876 (basis of record)
Aeodes marginata (Roussel) F.Schmitz, 1894 accepted as Felicinia marginata (Roussel) Manghisi, Le Gall, Ribera, Gargiulo & Morabito, 2014 (basis of record)
Agardhiella F.Schmitz, 1897 (basis of record)
Agardhiella subulata (C.Agardh) Kraft & M.J.Wynne, 1979 (additional source)

European waters (ERMS scope) for Acanthophora muscoides (Linnaeus) Bory de Saint-Vincent, 1828 
European waters (ERMS scope) for Acanthophora nayadiformis (Delile) Papenfuss, 1968 
European waters (ERMS scope) for Acinetospora crinita (Carmichael) Sauvageau, 1899 
European waters (ERMS scope) for Acrochaete cladophorae (Hornby) R.Nielsen, 1995 
European waters (ERMS scope) for Acrochaete geniculata (N.L.Gardner) O'Kelly, 1983 
European waters (ERMS scope) for Acrochaetium alariae (Jónsson) Bornet, 1904 
European waters (ERMS scope) for Acrochaetium balticum (Rosenvinge) Aleem & Schulz, 1952 
European waters (ERMS scope) for Acrochaetium barbadensis (Vickers) Borgesen, 1915 
European waters (ERMS scope) for Acrochaetium battersianum Hamel, 1927 
European waters (ERMS scope) for Acrochaetium boergesenii Schiffner, 1931 
European waters (ERMS scope) for Acrochaetium brebneri (Batters) Hamel, 1928 
European waters (ERMS scope) for Acrochaetium canariense Børgesen, 1927 
European waters (ERMS scope) for Acrochaetium catenulatum M.Howe, 1914 
European waters (ERMS scope) for Acrochaetium cheminii Feldmann, 1954 
European waters (ERMS scope) for Acrochaetium corymbiferum (Thuret) Batters, 1902 
European waters (ERMS scope) for Acrochaetium cymopoliae Børgesen, 1927 
European waters (ERMS scope) for Acrochaetium cytophagum (Rosenvinge) Hamel, 1927 
European waters (ERMS scope) for Acrochaetium densum (K.M.Drew) Papenfuss, 1945 
European waters (ERMS scope) for Acrochaetium duboscqii Feldmann, 1935 
European waters (ERMS scope) for Acrochaetium dumontiae (Rosenvinge) Hamel, 1927 
European waters (ERMS scope) for Acrochaetium emergens (Rosenvinge) Weber Bosse, 1921 
European waters (ERMS scope) for Acrochaetium endozoicum (Darbishire) Batters, 1902 
European waters (ERMS scope) for Acrochaetium extensum Ercegovic, 1957 
European waters (ERMS scope) for Acrochaetium gynandrum (Rosenvinge) Hamel, 1927 
European waters (ERMS scope) for Acrochaetium hauckii Schiffner, 1916 
European waters (ERMS scope) for Acrochaetium humile (Rosenvinge) Børgesen, 1915 
European waters (ERMS scope) for Acrochaetium immersum (Rosenvinge) Hamel, 1927 
European waters (ERMS scope) for Acrochaetium inclusum (Levring) Papenfuss, 1945 
European waters (ERMS scope) for Acrochaetium incrassatum Ercegovic, 1957 
European waters (ERMS scope) for Acrochaetium kylinii Hamel, 1927 
European waters (ERMS scope) for Acrochaetium lenormandii (Suhr ex Kützing) Nägeli, 1862 
European waters (ERMS scope) for Acrochaetium leptonema (Rosenvinge) Børgesen, 1915 
European waters (ERMS scope) for Acrochaetium liagorae Børgesen, 1915 
European waters (ERMS scope) for Acrochaetium lorrain-smithiae (Lyle) L.Newton, 1931 
European waters (ERMS scope) for Acrochaetium macula (Rosenvinge) Hamel, 1927 
European waters (ERMS scope) for Acrochaetium mediterraneum (Levring) Athanasiadis, 2003 
European waters (ERMS scope) for Acrochaetium microfilum C.-C.Jao, 1936 
European waters (ERMS scope) for Acrochaetium microscopicum (Nägeli ex Kützing) Nägeli, 1858 
European waters (ERMS scope) for Acrochaetium minutissimum (Shur) Nägeli, 1861 
European waters (ERMS scope) for Acrochaetium minutum (Suhr) Hamel, 1927 
European waters (ERMS scope) for Acrochaetium mirabilis (Suhr) Nägeli, 1862 
European waters (ERMS scope) for Acrochaetium molinieri Coppejans & Boudouresque, 1976 
European waters (ERMS scope) for Acrochaetium moniliforme (Rosenvinge) Børgesen, 1915 
European waters (ERMS scope) for Acrochaetium nitophyllii (Levring) Papenfuss, 1945 
European waters (ERMS scope) for Acrochaetium pallens (Zanardini) Nägeli, 1862 
European waters (ERMS scope) for Acrochaetium parvulum (Kylin) Hoyt, 1920 
European waters (ERMS scope) for Acrochaetium pulchellum Børgesen, 1915 
European waters (ERMS scope) for Acrochaetium radiatum C.-C.Jao, 1936 
European waters (ERMS scope) for Acrochaetium reductum (Rosenvinge) Hamel, 1927 
European waters (ERMS scope) for Acrochaetium robustum Børgesen, 1915 
European waters (ERMS scope) for Acrochaetium rosulata (Rosenvinge) Papenfuss 
European waters (ERMS scope) for Acrochaetium sanctae-mariae (Darbishire) Hamel, 1927 
European waters (ERMS scope) for Acrochaetium savianum (Meneghini) Nägeli, 1862 
European waters (ERMS scope) for Acrochaetium secundatum (Lyngbye) Nägeli, 1858 
European waters (ERMS scope) for Acrochaetium seiriolanum (Gibson) Rosenvinge, 1924 
European waters (ERMS scope) for Acrochaetium sparsum (Harvey) Nägeli, 1862 
European waters (ERMS scope) for Acrochaetium stilophorae (Levring) Kylin, 1944 
European waters (ERMS scope) for Acrochaetium subpinnatum Bornet ex Hamel, 1927 
European waters (ERMS scope) for Acrochaetium subseriatum Børgesen, 1932 
European waters (ERMS scope) for Acrochaetium subtilissimum (Kützing) Hamel, 1927 
European waters (ERMS scope) for Acrochaetium unifilum C.-C.Jao, 1936 
European waters (ERMS scope) for Acrochaetium virgatulum (Harvey) Batters, 1902 
European waters (ERMS scope) for Acrocytis groenlandica Rosenvinge 
European waters (ERMS scope) for Acrodiscus vidovichii (Meneghini) Zanardini, 1868 
European waters (ERMS scope) for Acrosiphonia arcta (Dillwyn) Gain, 1912 
European waters (ERMS scope) for Acrosiphonia arctiuscula (Kützing) Jónsson 
European waters (ERMS scope) for Acrosiphonia flagellata Kjellman, 1893 
European waters (ERMS scope) for Acrosiphonia grandis Kjelmann, 1893 
European waters (ERMS scope) for Acrosiphonia incurva Kjellman, 1893 
European waters (ERMS scope) for Acrosiphonia sonderi (Kützing) Kornmann, 1962 
European waters (ERMS scope) for Acrosiphonia spinescens (Kützing) Kjellman, 1893 
European waters (ERMS scope) for Acrosorium venulosum (Zanardini) Kylin, 1924 
European waters (ERMS scope) for Acrospongium ralfsioides Schiffner, 1916 
European waters (ERMS scope) for Acrosymphyton purpuriferum (J.Agardh) G.Sjöstedt, 1926 
European waters (ERMS scope) for Acrosymphyton taylorii I.A.Abbott, 1962 
European waters (ERMS scope) for Acrothamnion preissii (Sonder) E.M.Wollaston, 1968 
European waters (ERMS scope) for Acrothrix gracilis Kylin, 1907 
European waters (ERMS scope) for Adriogloia adriatica Ercegovic, 1955 
European waters (ERMS scope) for Aeodes marginata (Roussel) F.Schmitz, 1894 
European waters (ERMS scope) for Agardhiella subulata (C.Agardh) Kraft & M.J.Wynne, 1979 
European waters (ERMS scope) for Aglaothamnion bipinnatum (P.Crouan & H.Crouan) Feldmann & G.Feldmann, 1948 
European waters (ERMS scope) for Aglaothamnion caudatum (J.Agardh) Feldmann-Mazoyer, 1941 
European waters (ERMS scope) for Aglaothamnion cordatum (Børgesen) Feldmann-Mazoyer, 1941 
European waters (ERMS scope) for Aglaothamnion diaphanum L'Hardy-Halos & Maggs, 1991 
European waters (ERMS scope) for Aglaothamnion fasciculatum (Harvey) Maggs & L'Hardy-Halos, 1993 
European waters (ERMS scope) for Aglaothamnion feldmanniae Halos, 1965 
European waters (ERMS scope) for Aglaothamnion gallicum (Nägeli) Halos ex Ardré, 1970 
European waters (ERMS scope) for Aglaothamnion hookeri (Dillwyn) Maggs & Hommersand, 1993 
European waters (ERMS scope) for Aglaothamnion priceanum Maggs, Guiry & Rueness, 1991 
European waters (ERMS scope) for Aglaothamnion pseudobyssoides (P.Crouan & H.Crouan) Halos, 1965 
European waters (ERMS scope) for Aglaothamnion roseum (Roth) Maggs & L'Hardy-Halos, 1993 
European waters (ERMS scope) for Aglaothamnion sepositum (Gunnerus) Maggs & Hommersand, 1993 
European waters (ERMS scope) for Aglaothamnion tenuissimum (Bonnemaison) Feldmann-Mazoyer, 1941 
European waters (ERMS scope) for Aglaothamnion tripinnatum (C.Agardh) Feldmann-Mazoyer, 1941 
European waters (ERMS scope) for Ahnfeltia plicata (Hudson) E.M.Fries, 1836 
European waters (ERMS scope) for Ahnfeltiopsis devoniensis (Greville) P.C.Silva & DeCew, 1992 
European waters (ERMS scope) for Ahnfeltiopsis pusilla (Montagne) P.C.Silva & DeCew, 1992 
European waters (ERMS scope) for Aiolocolax pulchellus Pocock, 1956 
European waters (ERMS scope) for Alaria esculenta (Linnaeus) Greville, 1830 
European waters (ERMS scope) for Alsidium corallinum C.Agardh, 1827 

 Spelling

 for Lithophyllum duckerae Woelkerling, 1983

Lithophyllum duckeri Woelkerling, 1983 [details]

 Spelling

 for Lithophyllum vickersii M.Lemoine

Lithophyllum vickersiae M. Lemoine, 1929 [details]

 Taxonomy

 for Coccomyxa Schmidle, 1901

Also in database as valid genus in Myxidiidae (Myxospora)-needs checking [details]

 Taxonomy

 for Saccorhiza Bachelot de la Pylaie, 1830

Also in database as valid genus in Hippocrepinidae [details]