Acoela (basis of record)
Acrorhynchides Strand, 1928 (additional source)
Acrorhynchides robustus (Karling, 1931) Strand, 1928 (additional source)
Adenorhynchus Meixner, 1938 (additional source)
Adenorhynchus balticus Meixner, 1938 (additional source)
Amphirhynchus Schilke, 1970 (additional source)
Amphirhynchus caudatus Schilke, 1970 (additional source)
Anaperus Graff, 1911 accepted as Thalassoanaperus Hernandez, 2018 (additional source)
Anaperus tvaerminnensis (Luther, 1912) accepted as Thalassoanaperus tvaerminnensis (Luther, 1912) (additional source)
Anthopharynx Karling, 1940 (additional source)
Anthopharynx vaginatus Karling, 1940 (additional source)
Archiloa de Beauchamp, 1910 (additional source)
Archiloa petiti Ax, 1956 (additional source)
Archilopsis Meixner, 1938 (additional source)
Archilopsis arenaria Martens, Curini-Galletti & Pucinelli, 1989 (additional source)
Archilopsis marifuga Martens, Curini-Galletti & Pucinelli, 1989 (additional source)
Archimonocelididae Meixner, 1938 (basis of record)
Archimonocelis Meixner, 1938 (additional source)
Archimonocelis oostendensis Martens & Schockaert, 1981 (additional source)
Archimonotresis Meixner, 1938 (additional source)
Archimonotresis limophila Meixner, 1938 (additional source)
Astrotorhynchus Graff, 1905 (additional source)
Astrotorhynchus bifidus (McIntosh, 1874) Graff, 1905 (additional source)
Aulopharynx Ehlers, 1972 (additional source)
Aulopharynx aestuarius Ehlers, 1972 (additional source)
Baicalellia Nasonov, 1930 (additional source)
Baicalellia brevituba accepted as Baicalellia brevitubus (Luther, 1918) Nasonov, 1930 (additional source)
Baicalellia subsalina Ax, 1954 (additional source)
Bothriomolus Hallez, 1909 (additional source)
Bothriomolus balticus Meixner, 1938 (additional source)
Bradynectes Rieger, 1971 (additional source)
Bradynectes sterreri Rieger, 1971 (additional source)
Bresslauilla Reisinger, 1929 (additional source)
Bresslauilla relicta Reisinger, 1929 (additional source)
Brinkmanniella Luther, 1943 (additional source)
Brinkmanniella macrostomoides Luther, 1948 (additional source)
Byrsophlebidae Graff, 1882 (additional source)
Carcharodorhynchus Meixner, 1938 (additional source)
Carcharodorhynchus flavidus Brunet, 1967 (additional source)
Carcharodorhynchus isolatus Schilke, 1970 (additional source)
Carcharodorhynchus listensis Schilke, 1970 (additional source)
Carcharodorhynchus subterraneus Meixner, 1938 (additional source)
Carenscoilia Sopott, 1972 (additional source)
Carenscoilia bidentata Sopott, 1972 (additional source)
Carenscoilia biforamen Sopott, 1972 (additional source)
Castrada Schmidt, 1861 (additional source)
Catenulida (basis of record)
Cheliplana de Beauchamp, 1927 (additional source)
Cheliplana boadeni Schilke, 1970 (additional source)
Cheliplana marcusi (Karling, 1956) Karling, 1983 (additional source)
Cheliplana remanei (Meixner, 1928) Karling, 1983 (additional source)
Cheliplana stylifera Karling, 1949 (additional source)
Cheliplanilla Meixner, 1938 (additional source)
Cheliplanilla caudata Meixner, 1938 (additional source)
Cheliplanilla rubra Schilke, 1970 (additional source)
Cicerina Giard, 1904 (additional source)
Cicerinidae Meixner, 1928 (additional source)
Ciliopharyngiella Ax, 1952 (additional source)
Ciliopharyngiella constricta Martens & Schockaert, 1981 (additional source)
Ciliopharyngiellidae Ax, 1952 (additional source)
Cirrifera Sopott, 1972 (additional source)
Cirrifera aculeata (Ax, 1951) (additional source)
Cirrifera dumosa Sopott, 1972 (additional source)
Coelogynopora Steinböck, 1924 (additional source)
Coelogynopora axi Sopott, 1972 (additional source)
Coelogynopora biarmata Steinböck, 1924 (additional source)
Coelogynopora forcipis Sopott-Ehlers, 1976 (additional source)
Coelogynopora gynocotyla Steinböck, 1924 (additional source)
Coelogynopora solifer Sopott, 1972 (additional source)
Coelogynoporidae Karling, 1966 (additional source)
Coronhelmis Luther, 1948 (additional source)
Coronhelmis multispinosus Luther, 1948 (additional source)
Cylindrostoma Ørsted, 1845 (additional source)
Cylindrostoma fingalianum (Claparède, 1861) (basis of record)
Cystiplana Karling, 1964 (additional source)
Cystiplana paradoxa Karling, 1964 (additional source)
Cystiplanidae Karling, 1964 (additional source)
Dalyelliidae Graff, 1905 (additional source)
Dalyellioidarum (basis of record)
Diascorhynchidae Meixner, 1928 (additional source)
Diascorhynchus Meixner, 1928 (additional source)
Diascorhynchus rubrus Boaden, 1963 (additional source)
Diascorhynchus serpens Karling, 1949 (additional source)
Dochmiotrema Hofsten, 1907 (additional source)
Dochmiotrema limicola Hofsten, 1907 (additional source)
Dolichomacrostomidae Rieger, 1971 (additional source)
Doliopharynx Ehlers, 1972 (additional source)
Doliopharynx geminocirro Ehlers, 1972 (additional source)
Duplominona Karling, 1966 (additional source)
Duplominona septentrionalis Martens, 1983 (additional source)
Duploperaclistus Martens, 1983 (additional source)
Duploperaclistus circocirrus Martens, 1983 (additional source)
Eukalyptorhynchia (basis of record)
Gnathorhynchidae Meixner, 1929 (additional source)
Gnathorhynchus Meixner, 1929 (additional source)
Gnathorhynchus conocaudatus Meixner, 1929 (additional source)
Graffillidae Graff, 1905 (additional source)
Gyratrix Ehrenberg, 1831 (additional source)
Gyratrix hermaphroditus Ehrenberg, 1831 (additional source)
Halammovortex Karling, 1943 (additional source)