Achnanthidium fulla (J.R.Carter) M.Aboal, 2003 accepted as
Achnanthes fulla J.R.Carter, 1970 (new combination reference)
Achnanthidium subsalsum (J.B.Petersen) M.Aboal, 2003 accepted as
Achnanthes subsalsa J.B.Petersen, 1928 (new combination reference)
Cosmioneis pusilla var. incognita (Krasske) M.Aboal, 2003 accepted as
Navicula incognita Krasske, 1932 (new combination reference)
Craticula cuspidata var. media (Meister) M.Aboal, 2003 accepted as
Navicula cuspidata var. media Meister, 1912 (new combination reference)
Ctenophora pulchella var. lanceolata (O'Meara) L.Bukhtiyarova, 1995 accepted as
Synedra pulchella f. lanceolata O'Meara, 1875 (new combination reference)
Diadesmis contenta var. parallela (J.B.Petersen) Hamilton, 1995 accepted as
Humidophila parallela (Petersen) Furey, Manoylov & R.L.Lowe, 2020 (new combination reference)
Eunotia bilunaris var. capitata (Grunow) M.Aboal, 2003 accepted as
Synedra lunaris var. capitata Grunow, 1862 (new combination reference)
Fragilariforma virescens var. elliptica (Hustedt) E.Y.Haworth & M.G.Kelly accepted as
Fragilaria virescens var. elliptica Hustedt, 1913 accepted as
Fragilariforma virescens var. elliptica (Hustedt) Kharitonov, 2005 (new combination reference)
Gomphonema angustum var. lunatum (H.Germain) M.Aboal, 2003 accepted as
Gomphonema intricatum var. lunata Germain, 1981 (new combination reference)
Grunowia solgensis (Cleve-Euler) M.Aboal, 2003 accepted as
Nitzschia solgensis Cleve-Euler, 1952 (new combination reference)
Karayevia oblongella (Østrup) M.Aboal, 2003 accepted as
Achnanthes oblongella Østrup, 1902 (new combination reference)
Kolbesia gessneri (Hustedt) M.Aboal, 2003 accepted as
Achnanthes gessneri Hustedt, 1953 (new combination reference)
Luticola lanceolata (Frenguelli) Levkov, Metzeltin & A.Pavlov, 2013 (source of synonymy)
Luticola mutica var. lanceolata (Frenguelli) M.Aboal, 2003 accepted as
Luticola lanceolata (Frenguelli) Levkov, Metzeltin & A.Pavlov, 2013 (new combination reference)
Melosira lineata var. subangularis (Grunow) M.Aboal, 2003 accepted as
Melosira juergensii var. subangularis Grunow, 1882 (new combination reference)
Parlibellus protractus var. ellipticus (Gallik) M.Aboal, 2003 accepted as
Navicula protracta var. elliptica Gallik, 1935 (new combination reference)
Parlibellus protractus var. subcapitatus (Wislouch & Poretzsky) M.Aboal, 2003 accepted as
Navicula lundstroemii var. subcapitata Wislouch & Poretzsky, 1924 (new combination reference)
Placoneis placentula var. lanceolata (Grunow) M.Aboal, 2003 accepted as
Navicula tumida var. lanceolata Grunow, 1860 (new combination reference)
Planothidium conspicuum (A.Mayer) M.Aboal, 2003 accepted as
Achnanthes conspicua var. conspicua A.Mayer, 1919 (new combination reference)
Psammothidium curtissimum (J.R.Carter) M.Aboal, 2003 accepted as
Achnanthes curtissima J.R.Carter, 1963 accepted as
Psammothidium microscopicum (Cholnoky) S. Blanco, 2016 (new combination reference)
Psammothidium hustedtii (Krasske) Mayama, 2002 accepted as
Cocconeis hustedtii Krasske, 1923 (new combination reference)
Psammothidium montanum (Krasske) Mayuma, 2002 accepted as
Achnanthes montana var. montana Krasske, 1929 (new combination reference)
Psammothidium semiapertum (Hustedt) M.Aboal, 2003 accepted as
Cocconeis semiaperta Hustedt, 1945 (new combination reference)
Rossithidium nodosum (Cleve) M.Aboal, 2003 accepted as
Achnanthes nodosa Cleve, 1900 (new combination reference)
Rossithidium petersenii (Hustedt) Round & Bukhtiyarova, 1996 accepted as
Achnanthes petersenii var. petersenii Hustedt, 1936 (new combination reference)
Sellaphora joubaudii (H.Germain) M.Aboal, 2003 accepted as
Navicula joubaudii H.Germain, 1982 (new combination reference)
Sellaphora pupula var. rostrata (Hustedt) M.Aboal, 2003 accepted as
Navicula pupula var. rostrata Hustedt, 1911 (new combination reference)
Staurosirella pinnata var. trigona (Brun & Héribaud-Joseph) M.Aboal & P.C.Silva, 2004 (new combination reference)
Tabularia affinis var. acuminata (Grunow) M.Aboal, 2003 accepted as
Synedra affinis var. acuminata Grunow, 1881 (new combination reference)
Tabularia grandis (Mereschkowsky) M.Aboal, 2003 accepted as
Synedra grandis var. grandis Mereschkowsky, 1902 (new combination reference)
Tryblionella gracilis var. subsalina (O'Meara) M.Aboal, 2003 accepted as
Tryblionella subsalina O'Meara, 1872 (new combination reference)
Tryblionella hungarica var. linearis (Grunow) M.Aboal, 2003 accepted as
Nitzschia hungarica f. linearis Grunow in Cleve & Grunow, 1880 (new combination reference)
Ulnaria delicatissima var. angustissima (Grunow) M.Aboal & P.C.Silva, 2004 accepted as
Synedra delicatissima var. angustissima Grunow, 1881 (new combination reference)
Ulnaria oxyrhyncus (Kützing) Aboal in Aboal, Alvarez-Cobelas, Cambra & Ector, 2003 accepted as
Synedra oxyrhynchus var. oxyrhynchus Kützing, 1844 (new combination reference)
Ulnaria ulna var. aequalis (Kützing) M.Aboal, 2003 accepted as
Frustulia aequalis Kützing, 1833 (new combination reference)
Ulnaria ulna var. amphirhynchus (Ehrenberg) M.Aboal, 2003 accepted as
Synedra amphirhynchus var. amphirhynchus Ehrenberg, 1843 (new combination reference)
Ulnaria ulna var. notata (Kützing) M.Aboal, 2003 accepted as
Synedra notata Kützing, 1844 (new combination reference)
Ulnaria ulna var. spathulifera (Grunow) M.Aboal, 2003 accepted as
Synedra spathulifera Grunow, 1881 (new combination reference)
Ulnaria ulna var. splendens (Kützing) M.Aboal, 2003 accepted as
Frustulia splendens Kützing, 1833 (new combination reference)
Ulnaria ulna var. subaequalis (Grunow) M.Aboal, 2003 accepted as
Synedra subaequalis f. subaequalis Grunow in Van Heurck, 1881 (new combination reference)