Abedinium Loeblich & A.R.Loeblich, 1966 (additional source)
Abedinium dasypus (Cachon & Cachon-Enjumet) Loeblich Jr & Loeblich III, 1966 (additional source)
Abollifer Vørs, 1992 (additional source)
Abollifer prolabens Vørs, 1992 (additional source)
Acanthocorbis apoda (Leadbeater) Hara & Takahashi, 1984 (additional source)
Acanthocorbis asymmetrica (Thomsen) Hara & Takahashi, 1984 (additional source)
Acanthocorbis campanula (Espeland) Thomsen, 1991 (additional source)
Acanthocorbis haurakiana Thomsen, 1991 (additional source)
Acanthocorbis unguiculata (Thomsen) Hara & Takahashi, 1984 (additional source)
Acanthocorbis weddellensis Thomsen, Garrison & Kosman, 1997 (additional source)
Acanthoeca brevipoda W.Ellis, 1930 (additional source)
Acanthoeca spectabilis W.N.Ellis, 1930 (basis of record)
Acanthoeca spectabilis W.N.Ellis, 1930 (additional source)
Acanthoecaceae (basis of record)
Acanthoecopsis apoda Leadbeater, 1972 accepted as Acanthocorbis apoda (Leadbeater) Hara & Takahashi, 1984 (additional source)
Acanthoecopsis asymmetrica Thomsen (additional source)
Acanthoecopsis campanula Espeland, 1986 accepted as Acanthocorbis campanula (Espeland) Thomsen, 1991 (additional source)
Acanthoecopsis spiculifera R.E.Norris, 1965 (additional source)
Acanthoecopsis unguiculata Thomsen, 1973 accepted as Acanthocorbis unguiculata (Thomsen) Hara & Takahashi, 1984 (additional source)
Acanthoica acanthifera Lohmann ex Lohmann, 1913 (additional source)
Acanthoica quattrospina Lohmann, 1903 (additional source)
Acanthophora J.V.Lamouroux, 1813 (additional source)
Acanthophora muscoides (Linnaeus) Bory de Saint-Vincent, 1828 (basis of record)
Acanthophora muscoides (Linnaeus) Bory de Saint-Vincent, 1828 (additional source)
Acanthophora nayadiformis (Delile) Papenfuss, 1968 (basis of record)
Acanthosphaera Lemmermann, 1899 (basis of record)
Acanthosphaera zachariasii Lemmermann, 1899 (basis of record)
Acetabularia J.V.Lamouroux, 1812 (additional source)
Acetabularia acetabulum (Linnaeus) P.C. Silva, 1952 (basis of record)
Acetabularia caliculus J.V.Lamouroux, 1824 (basis of record)
Acetabularia moebii Solms-Laubach, 1895 accepted as Parvocaulis parvulus (Solms-Laubach) S.Berger, Fettweiss, Gleissberg, Liddle, U.Richter, Sawitzky & Zuccarello, 2003 (basis of record)
Acetabularia parvula Solms-Laubach, 1895 accepted as Parvocaulis parvulus (Solms-Laubach) S.Berger, Fettweiss, Gleissberg, Liddle, U.Richter, Sawitzky & Zuccarello, 2003 (additional source)
Acetabularia polyphysoides P.Crouan & H.Crouan, 1865 accepted as Parvocaulis polyphysoides (P.Crouan & H.Crouan) S.Berger & al. ex J.N.Norris & D.L.Ballantine, 2023 (basis of record)
Acetabularia polyphysoides P.Crouan & H.Crouan, 1865 accepted as Parvocaulis polyphysoides (P.Crouan & H.Crouan) S.Berger & al. ex J.N.Norris & D.L.Ballantine, 2023 (additional source)
Acetabularia subg. Acetabularia (basis of record)
Acetabularia subg. Acicularia (basis of record)
Acetabularia wettsteinii Schussnig, 1930 accepted as Parvocaulis parvulus (Solms-Laubach) S.Berger, Fettweiss, Gleissberg, Liddle, U.Richter, Sawitzky & Zuccarello, 2003 (basis of record)
Achradina pulchra Lohmann, 1903 accepted as Monaster rete F.Schütt, 1895 (basis of record)
Achradina pulchra Lohmann, 1903 accepted as Monaster rete F.Schütt, 1895 (additional source)
Achroonema lentum Skuja, 1956 (basis of record)
Achroonema proteiforme Skuja, 1956 (basis of record)
Acinetospora Bornet, 1891 (additional source)
Acinetospora crinita (Carmichael) Sauvageau, 1899 (additional source)
Acinetosporaceae Hamel ex J. Feldmann, 1937 (basis of record)
Acrochaete N.Pringsheim, 1862 accepted as Ulvella P.L.Crouan & H.M.Crouan, 1859 (additional source)
Acrochaete cladophorae (Hornby) R.Nielsen, 1995 accepted as Ulvella cladophorae (Hornby) A.C.Mathieson & Dawes, 2017 (basis of record)
Acrochaete cladophorae (Hornby) R.Nielsen, 1995 accepted as Ulvella cladophorae (Hornby) A.C.Mathieson & Dawes, 2017 (additional source)
Acrochaete flustrae (Reinke) O'Kelly, 2006 accepted as Epicladia flustrae Reinke, 1889 (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)
Acrochaete geniculata (N.L.Gardner) O'Kelly, 1983 accepted as Ulvella geniculata (N.L.Gardner) R.Nielsen, C.J.O'Kelly & B. Wysor, 2013 (additional source)
Acrochaete heteroclada J.A.Correa & R.Nielsen, 1988 accepted as Ulvella heteroclada (Correa & R.Nielsen)R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaete inflata (Ercegovic) Gallardo, Gómez Garreta, M.A.Ribera, Cormaci, G.Furnari, Giaccone & Boudouresque, 1993 accepted as Ulvella inflata (Ercegovic) R.Nielsen, C.J.O'Kelly & B. Wysor, 2013 (additional source)
Acrochaete leptochaete (Huber) R.Nielsen, 1983 accepted as Ulvella leptochaete (Huber) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaete operculata J.A.Correa & R.Nielsen, 1988 accepted as Ulvella operculata (Correa & R.Nielsen) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaete parasitica Oltmanns, 1894 accepted as Ulvella parasitica (Oltmanns) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaete polymorpha (L.Moewus) R.Nielsen, 1988 accepted as Ulvella leptochaete (Huber) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaete repens Pringsheim, 1862 accepted as Ulvella repens (Pringsheim) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaete taylorii (Thivy) O'Kelly, 2006 accepted as Ulvella taylorii (Thivy) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (basis of record)
Acrochaete viridis (Reinke) R.Nielsen, 1979 accepted as Ulvella viridis (Reinke) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaete wittrockii (Wille) R.Nielsen, 1983 accepted as Ulvella wittrockii (Wille) R.Nielsen, C.J.O'Kelly & B.Wysor, 2013 (additional source)
Acrochaetium Nägeli, 1858 (additional source)
Acrochaetium alariae (Jónsson) Bornet, 1904 (additional source)
Acrochaetium asparagopsis (Chemin) Papenfuss, 1945 accepted as Colaconema asparagopsis Chemin, 1926 (additional source)
Acrochaetium attenuatum (Rosenvinge) Hamel, 1927 accepted as Colaconema attenuatum (Rosenvinge) R.Nielsen, 1994 accepted as Acrochaetium densum (K.M.Drew) Papenfuss, 1945 accepted as Acrochaetium catenulatum M.Howe, 1914 (basis of record)
Acrochaetium balticum (Rosenvinge) Aleem & Schulz, 1952 (additional source)
Acrochaetium barbadense (Vickers) Børgesen, 1915 (basis of record)
Acrochaetium battersianum Hamel, 1927 (basis of record)
Acrochaetium battersianum Hamel, 1927 (additional source)
Acrochaetium boergesenii Schiffner, 1931 (additional source)
Acrochaetium bonnemaisoniae (Batters) Feldmann & G.Feldmann, 1940 accepted as Colaconema bonnemaisoniae Batters, 1896 (additional source)
Acrochaetium brebneri (Batters) Hamel, 1928 (basis of record)
Acrochaetium brebneri (Batters) Hamel, 1928 (additional source)
Acrochaetium caespitosum (J.Agardh) Nägeli, 1862 accepted as Colaconema caespitosum (J.Agardh) Jackelman, Stegenga & J.J.Bolton, 1991 (additional source)
Acrochaetium canariense Børgesen, 1927 (additional source)
Acrochaetium catenulatum M.Howe, 1914 (basis of record)
Acrochaetium catenulatum M.Howe, 1914 (additional source)
Acrochaetium cheminii Feldmann, 1954 (basis of record)
Acrochaetium cheminii Feldmann, 1954 (additional source)
Acrochaetium chylocladiae (Batters) Batters, 1902 accepted as Colaconema chylocladiae Batters, 1896 (additional source)
Acrochaetium codicola Børgesen, 1927 accepted as Colaconema codicola (Børgesen) Stegenga, J.J.Bolton & R.J.Anderson, 1997 (basis of record)
Acrochaetium codicola Børgesen, 1927 accepted as Colaconema codicola (Børgesen) Stegenga, J.J.Bolton & R.J.Anderson, 1997 (additional source)
Acrochaetium codii Hamel, 1927 accepted as Colaconema caespitosum (J.Agardh) Jackelman, Stegenga & J.J.Bolton, 1991 (basis of record)
Acrochaetium codii Hamel, 1927 accepted as Colaconema caespitosum (J.Agardh) Jackelman, Stegenga & J.J.Bolton, 1991 (additional source)
Acrochaetium collopodum (Rosenvinge) Hamel, 1927 (basis of record)
Acrochaetium corymbiferum (Thuret) Batters, 1902 accepted as Colaconema corymbiferum (Thuret) Alongi, Cormaci & G.Furnari, 2017 (basis of record)
Acrochaetium corymbiferum (Thuret) Batters, 1902 accepted as Colaconema corymbiferum (Thuret) Alongi, Cormaci & G.Furnari, 2017 (additional source)
Acrochaetium crassipes (Børgesen) Børgesen, 1915 (basis of record)
Acrochaetium crassipes (Børgesen) Børgesen, 1915 (additional source)
Acrochaetium cymopoliae Børgesen, 1927 (additional source)
Acrochaetium cytophagum (Rosenvinge) Hamel, 1927 (basis of record)
Acrochaetium cytophagum (Rosenvinge) Hamel, 1927 (additional source)
Acrochaetium daviesii (Dillwyn) Nägeli, 1862 accepted as Colaconema daviesii (Dillwyn) Stegenga, 1985 (source of synonymy)
Acrochaetium densum (K.M.Drew) Papenfuss, 1945 accepted as Acrochaetium catenulatum M.Howe, 1914 (basis of record)
Acrochaetium densum (K.M.Drew) Papenfuss, 1945 accepted as Acrochaetium catenulatum M.Howe, 1914 (additional source)
Acrochaetium duboscqii Feldmann, 1935 (additional source)
Acrochaetium dumontiae (Rosenvinge) Hamel, 1927 (basis of record)
Acrochaetium dumontiae (Rosenvinge) Hamel, 1927 (additional source)
Acrochaetium efflorescens (J.Agardh) Nägeli, 1861 accepted as Grania efflorescens (J.Agardh) Kylin, 1944 (additional source)
Acrochaetium emergens (Rosenvinge) Weber Bosse, 1921 accepted as Colaconema emergens (Rosenvinge) R.Nielsen, 1994 (basis of record)
Acrochaetium emergens (Rosenvinge) Weber Bosse, 1921 accepted as Colaconema emergens (Rosenvinge) R.Nielsen, 1994 (additional source)

Belgian Exclusive Economic Zone for Aphanochaete repens A.Braun, 1850 
Belgian Exclusive Economic Zone for Scytosiphon lomentaria (Lyngbye) Link, 1833 
Europe for Pycnococcaceae R.R.L. Guillard 

English ant-like flower beetles for Anthicidae Latreille, 1819
English black siphon weed [from synonym] for Polysiphonia fucoides (Hudson) Greville, 1824
English bushy berry wrack [from synonym] for Cystoseira baccata (S.G.Gmelin, 1768) P.C.Silva, 1952
Swedish fjäderslick [from synonym] for Polysiphonia fucoides (Hudson) Greville, 1824

 Classification

 for Coolia Meunier, 1919

According to Algaebase, Coolia is situated within the family Peridiniaceae [details]

 Classification

 for Woloszynskia R.H.Thompson, 1951

According to Algaebase, Woloszynskia is situated in a seperate family: Woloszynskiaceae within the ordo of Cymnodiniales [details]

 Spelling

 for Chaetoceros affinis Lauder, 1864

Referred to as Chaetoceros affinis by some sources. [details]

 Spelling

 for Chaetoceros borealis Bailey, 1854

Referred to as Chaetoceros boreale by some sources. [details]

 Spelling

 for Chaetoceros compressus Lauder, 1864

Referred to as Chaetoceros compressum by some sources. [details]

 Spelling

 for Chaetoceros convolutus Castracane, 1886

Referred to as Chaetoceros convolutum by some sources. [details]

 Spelling

 for Chaetoceros peruvianum Brightwell, 1856

Referred to as Chaetoceros peruvianum by some sources. [details]

 Spelling

 for Chaetoceros schuttii Cleve

Referred to as Chaetoceros schuttii by some sources. [details]