Lioloma delicatulum (Cupp) Hasle, 1996
Lioloma elongatum (Grunow) Hasle, 1997
Lioloma pacificum (Cupp) Hasle, 1996
Thalassionema antiqua Schrader, 1973 (uncertain > unassessed )
Thalassionema bacillare (Heiden) Kolbe, 1955
Thalassionema bacillaris (Heiden & Kolbe) Kolbe, 1955 accepted as Spinigera bacillaris Heiden, 1928
Thalassionema bifurcum Kato & Suto, 2019 †
Thalassionema capitulata (Castracane) Hustedt, 1958 accepted as Synedra capitulata Castracane, 1886
Thalassionema claviformis Schrader, 1973 (uncertain > unassessed )
Thalassionema curvatum Kisselev, 1935 (uncertain > unassessed )
Thalassionema elegans Hustedt, 1958 (uncertain > unassessed )
Thalassionema frauenfeldii (Grunow) Tempère & Peragallo, 1910
Thalassionema frauenfeldii var. doljensis Tempère & Peragallo, 1910 (uncertain > unassessed )
Thalassionema frauenfeldii var. frauenfeldii (Grunow) Tempère & Peragallo, 1910 accepted as Thalassiothrix frauenfeldii Cleve, 1894 accepted as Thalassionema frauenfeldii (Grunow) Tempère & Peragallo, 1910
Thalassionema gelida (uncertain > unassessed )
Thalassionema gelida var. elongata M. Peragallo, 1921 (uncertain > unassessed )
Thalassionema gelida var. gelida M. Peragallo, 1921 (uncertain > unassessed )
Thalassionema hirosakiensis (Kanaya) Schrader, 1973 accepted as Fragilaria hirosakiensis Kanaya, 1959
Thalassionema javanicum (Grunow) Hasle in Hasle & Syvertsen, 1996 accepted as Thalassiothrix frauenfeldii var. javanica Grunow, 1881
Thalassionema kuroshioensis Sugie & Ko.Suzuki, 2015
Thalassionema lineatum Jousé, 1971 (uncertain > unassessed )
Thalassionema nitzschioides (Grunow) Mereschkowsky, 1902
Thalassionema nitzschioides f. curta (uncertain > unassessed )
Thalassionema nitzschioides f. nitzschioides (Grunow) Van Heurck, 1896 accepted as Synedra nitzschioides f. nitzschioides Grunow, 1862 represented as Thalassionema nitzschioides (Grunow) Mereschkowsky, 1902
Thalassionema nitzschioides var. acuminata (Grunow in Pantocsek) M. Peragallo, 1903 accepted as Synedra nitzschioides var. acuminata Grunow ex Pantocsek, 1886
Thalassionema nitzschioides var. antiqua (Schrader) Moreno-Ruiz in Moreno-Ruiz & Licea, 1995 accepted as Thalassionema antiqua Schrader, 1973
Thalassionema nitzschioides var. australis Cleve-Euler, 1949 (uncertain > unassessed )
Thalassionema nitzschioides var. capitulata (Castracane) Moreno-Ruiz in Moreno-Ruiz & Licea, 1995 accepted as Synedra capitulata Castracane, 1886
Thalassionema nitzschioides var. claviformis (Schrader) Moreno in Moreno-Ruiz & Carreno, 1993 accepted as Thalassionema claviformis Schrader, 1973
Thalassionema nitzschioides var. curvata (Castracane) Mereschkowsky, 1902 accepted as Thalassiothrix curvata Castracane, 1886
Thalassionema nitzschioides var. curvatum Mereschkowsky, 1902 (uncertain > unassessed )
Thalassionema nitzschioides var. gracilis Heiden & Kolbe, 1928 (uncertain > unassessed )
Thalassionema nitzschioides var. incurvata Heiden & Kolbe, 1928 (uncertain > unassessed )
Thalassionema nitzschioides var. inflata Heiden & Kolbe, 1928 (uncertain > unassessed )
Thalassionema nitzschioides var. irregulare Jurilj, 1957 (uncertain > unassessed )
Thalassionema nitzschioides var. javanica (Grunow in Van Heurck) Peragallo & Peragallo, 1901 accepted as Thalassiothrix nitzschioides var. javanica Grunow in Van Heurck, 1881
Thalassionema nitzschioides var. javanicum (Grunow) Heiden in Heiden & Kolbe, 1928 accepted as Thalassiothrix nitzschioides var. javanica Grunow in Van Heurck, 1881
Thalassionema nitzschioides var. lanceolata (Grunow in Van Heurck) Peragallo & Peragallo, 1901 accepted as Thalassiothrix nitzschioides var. lanceolata Grunow in Van Heurck, 1881
Thalassionema nitzschioides var. lanceolatum Grunow, 1928 (uncertain > unassessed )
Thalassionema nitzschioides var. obtusa (Grunow in Van Heurck) M. Peragallo, 1903 accepted as Thalassiothrix nitzschioides var. obtusa Grunow in Van Heurck, 1881
Thalassionema nitzschioides var. obtusum (Grunow) Heiden in Heiden & Kolbe, 1928 accepted as Thalassiothrix nitzschioides var. obtusa Grunow in Van Heurck, 1881
Thalassionema nitzschioides var. parva (Heiden) emend Moreno-Ruiz in Moreno-Ruiz & Licea, 1995 (uncertain > unassessed )
Thalassionema nitzschioides var. parva Heiden & Kolbe, 1928 (uncertain > unassessed )
Thalassionema nitzschioides var. robusta Schrader emend Moreno-Ruiz in Moreno-Ruiz & Licea, 1995 (uncertain > unassessed )
Thalassionema nitzschioides var. schraderi (Akiba) Moreno-Ruiz in Moreno-Ruiz & Licea, 1995 accepted as Thalassionema schraderi Akiba, 1982
Thalassionema obtusa (Grunow) Andrews, 1976 accepted as Thalassiothrix nitzschioides var. obtusa Grunow in Van Heurck, 1881
Thalassionema pseudonitzschioides (Schuette & Schrader) Hasle in Hasle & Syvertsen, 1996 accepted as Thalassiothrix pseudonitzschioides G.Schuette & H.Schrader, 1982
Thalassionema robusta Schrader, 1973 (uncertain > unassessed )
Thalassionema schraderi Akiba, 1982 (uncertain > unassessed )
Thalassionema synedriforme (Greville) Hasle, 1999 (uncertain > unassessed )
Thalassiothrix acuta Karsten, 1905 (uncertain > unassessed )
Thalassiothrix africana Woodhead & Tweed, 1960 (uncertain > unassessed )
Thalassiothrix antarctica A.Schimper ex G.Karsten, 1905
Thalassiothrix antarctica f. antarctica Schimper ex Karsten, 1905 (uncertain > unassessed )
Thalassiothrix antarctica f. japonica Skvortzow, 1931 (uncertain > unassessed )
Thalassiothrix antarctica var. echinata Karsten, 1907 (uncertain > unassessed )
Thalassiothrix antarctica var. heteromorpha (Karsten) F.W. Mills, 1935 accepted as Thalassiothrix heteromorpha Karsten, 1907
Thalassiothrix antarctica var. tenuis Schimper in Karsten, 1905 (uncertain > unassessed )
Thalassiothrix centralis Meshcheryakova, 1960 (uncertain > unassessed )
Thalassiothrix clevei Henckel, 1925 (uncertain > unassessed )
Thalassiothrix curvata Castracane, 1886 (uncertain > unassessed )
Thalassiothrix delicatula Cupp, 1943 represented as Lioloma delicatulum (Cupp) Hasle, 1996
Thalassiothrix elongata Grunow, 1880 represented as Lioloma elongatum (Grunow) Hasle, 1997
Thalassiothrix fallax Cleve-Euler, 1917 (uncertain > unassessed )
Thalassiothrix fossilis Jurilj, 1957 (uncertain > unassessed )
Thalassiothrix frauenfeldii (Grunow) Grunow, 1880 accepted as Thalassionema frauenfeldii (Grunow) Tempère & Peragallo, 1910
Thalassiothrix frauenfeldii Cleve, 1894 accepted as Thalassionema frauenfeldii (Grunow) Tempère & Peragallo, 1910
Thalassiothrix frauenfeldii f. curvata (Castracane) Jørgensen, 1899 accepted as Thalassiothrix curvata Castracane, 1886
Thalassiothrix frauenfeldii f. curvata (Castracane) Jørgensen, 1905 (uncertain > unassessed )
Thalassiothrix frauenfeldii var. arctica Grunow in Van Heurck, 1881 (uncertain > unassessed )
Thalassiothrix frauenfeldii var. doljensis Tempère & Peragallo, 1915 (uncertain > unassessed )
Thalassiothrix frauenfeldii var. frauenfeldii (Grunow) Grunow in Cleve & Grunow, 1880 accepted as Asterionella frauenfeldii Grunow, 1863 represented as Thalassionema frauenfeldii (Grunow) Tempère & Peragallo, 1910
Thalassiothrix frauenfeldii var. javanica Grunow, 1881 (uncertain > unassessed )
Thalassiothrix frauenfeldii var. nitzschioides (Castracane) Jorgensen, 1900 accepted as Thalassiothrix curvata Castracane, 1886
Thalassiothrix frauenfeldii var. nitzschioides E. Jorgensen, 1900 (uncertain > unassessed )
Thalassiothrix frauenfeldii var. panama Smayda, 1966 (uncertain > unassessed )
Thalassiothrix frauenfeldii var. sinuata Tempère & Peragallo, 1910 (uncertain > unassessed )
Thalassiothrix frauenfeldii var. tenella Grunow in Van Heurck, 1881 (uncertain > unassessed )
Thalassiothrix frenellii Mironov, 1954 (uncertain > unassessed )
Thalassiothrix gibberula Hasle, 1960
Thalassiothrix heteromorpha Karsten, 1907 (uncertain > unassessed )
Thalassiothrix heteromorpha var. mediterranea (Pavillard) Hallegraeff, 1986 accepted as Thalassiothrix mediterranea var. mediterranea Pavillard, 1916
Thalassiothrix javanica (Grunow) Hustedt ex Meister, 1932 accepted as Thalassiothrix frauenfeldii var. javanica Grunow, 1881
Thalassiothrix lanceolata Hustedt, 1958 (uncertain > unassessed )
Thalassiothrix longissima Cleve & Grunow, 1880 (uncertain > unassessed )
Thalassiothrix longissima sensu Cupp, 1943 (uncertain > unassessed )
Thalassiothrix longissima f. gracilis Ostenfeld in Ostenfeld & Schmidt, 1901 (uncertain > unassessed )
Thalassiothrix longissima var. antarctica Cleve & Möller, 1878 (uncertain > unassessed )
Thalassiothrix longissima var. gibberula (Hasle) Hallegraeff, 1986 accepted as Thalassiothrix gibberula Hasle, 1960
Thalassiothrix longissima var. lanceolata (Hustedt) Hallegraeff, 1986 accepted as Thalassiothrix lanceolata Hustedt, 1958
Thalassiothrix longissima var. longissima Cleve & Grunow in Cleve & Moller, 1878 (uncertain > unassessed )
Thalassiothrix marina (Gregory) Grunow in Van Heurck, 1881 accepted as Meridion marinum Gregory, 1857
Thalassiothrix mediterranea Pavillard
Thalassiothrix mediterranea var. mediterranea Pavillard, 1916 (uncertain > unassessed )
Thalassiothrix mediterranea var. pacifica Cupp, 1943 represented as Lioloma pacificum (Cupp) Hasle, 1996
Thalassiothrix miocenica Schrader, 1973 (uncertain > unassessed )
Thalassiothrix monospina Schrader, 1974 (uncertain > unassessed )
Thalassiothrix nitzschioides (Grunow) Grunow, 1881 accepted as Thalassionema nitzschioides (Grunow) Mereschkowsky, 1902
Thalassiothrix nitzschioides f. curvata (Castracane) Jørgensen, 1905 accepted as Thalassiothrix curvata Castracane, 1886
Thalassiothrix nitzschioides var. acuminata (Grunow ex Pantocsek) De Toni, 1892 (uncertain > unassessed )