| Acelis (part) | "species" | Yeri & Kaburaki, 1918 | |
| Choeradoplana | abaiba | Carbayo, Silva, Riutort, & Alvarez-Presas, 2017 | |
| Plagiostomum | abboti | Karling, 1962 | |
| Dendrocoelides | abditum | (Kenk, 1940) | |
| Dendrocoelum | abditum | (Kenk, 1940) | |
| Paradendrocoelum | abditum | Kenk, 1940 | |
| Microplana | aberana | (Mell, 1904) | |
| Amblyplana | aberana | Mell, 1904 | |
| Dugesia | aberana | Neppi, 1904 | |
| Rhynchodemus | aberanus | (Mell, 1904) | |
| Stylochoplana | aberrans | Kato, 1944 | |
| Ilyplana | aberrans | Bock, 1925 | |
| Stylochoplana | aberrans | Kato, 1944 | |
| Ilyplana | aberrans | Bock, 1925 | |
| Itaipusa | aberrans | Diez, Aguirre, Reygel, & Artois, 2021 | |
| Crucimusculata | Aberrantospermata | Jondelius, Wallberg, Hooge, & Raikova, 2011 | |
| Protocotylus | flavus | abissorum | Timoshkin & Porfireva, 1989 |
| Planaria | aborensis | Whitehouse, 1913 | |
| Dugesia | aborensis | (Whitehouse, 1913) | |
| Crenobia | abscissa | (Ijima, 1887) | |
| Geopaludicola | absoloni | Komarek, 1919 | |
| Dugesia | absoloni | (Komarek, 1919) | |
| Euplanaria | absoloni | (Komarek, 1919) | |
| Geoplana | abundans | (Graff, 1899) | |
| Notogynaphallia | abundans | (Graff, 1899) | |
| Luteostriata | abundans | (Graff, 1899) | |
| marginata | abundans var. | Graff, 1899 | |
| Dalyellia | abursalis | Ruebush, 1937 | |
| Bhambathorhynchus | abursalis | Willems & Artois, 2017 | |
| Microdalyellia | abursalis | (Ruebush, 1937) | |
| Archotoplana | abutaensis | Tajika, 1983 | |
| Opisthocystis | abyssalis | Timoshkin, 1986 | |
| Geocentrophora | wagini | abyssalis | Timoshkin, 2004 |
| Fecampia | abyssicola | Christensen, 1981 | |
| Protomonotresinae | Acanthiella | Rieger & Sterrer, 1975 | |
| Karlingiinae | Acanthomacrostomum | Papi & Swedmark, 1959 | |
| Typhloplanidae | Acanthopharynx | Reisinger, 1924 | |
| Cannoninae | Acanthopseudomonocelis | Curini-Galletti & Cannon, 1995 | |
| Pseudocerotidae | Acanthozoon | Collingwood, 1876 | |
| Pseudocerotidae | Acanthozoon | Collingwood, 1876 | |
| Pseudoceros | (Acanthozoon) | Heath & McGregor, 1912 | |
| Gieysztoria | acariaia | Marcus, 1946 | |
| (Gieysztoria) | acariaia | Marcus, 1946 | |
| Phaenocora | unipunctata | acaudata | (Wese, 1942) |
| Fletchamia | quinquelineata | accentuata | (Steel, 1897) |
| quinquelineata | accentuata | Steel, 1897 | |
| Plehniidae | Acelis (part) | Plehn, 1896 | |
| Plagiostomidae | Acelis (part) | Diesing, 1862 | |
| Euneoophora | Acentrosomata | Egger, Lapraz, Tomiczek, et al., 2015 | |
| Bulbotoplana | acephala | Ax, 1956 | |
| Euryleptidae | Aceros | Lang, 1884 | |
| Euryleptinae | Aceros | Lang, 1884 | |
| Utelga | acerosa | Brunet, 1972 | |
| Itaipusa | acerosa | (Brunet, 1972) | |
| Euryleptidae | Acerotisa | Strand, 1928 | |
| Euryleptinae | Acerotisa | Strand, 1928 | |
| Cestoplanidae | Acestoplana | Faubel, 1983 | |
| Phaenocora | achaeorum | Nasonov, 1919 | |
| Temnocephalinae | Achenella | Cannon, 1993 | |
| Anaperidae | Achoerus | Beklemischev, 1914 | |
| Convolutidae | Achoerus | Beklemischev, 1914 | |
| Acholadidae | Acholades | Hickman & Olsen, 1955 | |
| Endoaxonemata | Acholadidae | Hickman & Olsen, 1955 | |
| Neodalyellida | Acholadidae | Hickman & Olsen, 1955 | |
| Plagiostomum | achromaticum | Mahan, 1946 | |
| Microstomum | achroophthalmum | Diesing, 1862 | |
| Temnosewellia | acicularis | Sewell, Cannon & Blair, 2006 | |
| Temnosewellia | acirra | Cannon & Sewell, 2001 | |
| Cicerinidae | Acirrostylus | Van Steenkiste, Volonterio, Schockaert & Artois, 2008 | |
| Plagiostomidae | Acmostomum | Schmarda, 1859 | |
| Xenacoela | Acoela | Uljanin, 1870 | |
| Xenacoelomorpha | Acoelomorpha | Ehlers, 1985 | |
| Actinoposthiidae | Acoelopelophila | Ceccolini & Cianferoni, 2022 | |
| Plagiostomum | acoluthum | Marcus, 1948 | |
| Polycladida | Acotylea | Lang, 1884 | |
| Polycladida (II) | Acotylea | Lang, 1884 | |
| Polycladida (II) | Acotylina | Pearse, 1936 | |
| Protoplanellinae | Acrochordonoposthia | Reisinger, 1924 | |
| Dendrocoelidae | Acromyadenium | de Beauchamp, 1931 | |
| Amakusaplana | acroporae | Rawlinson, Gillis, Billings & Borneman, 2011 | |
| Prosthiostomum | acroporae | Rawlinson, Gillis, Billings & Borneman, 2011 | |
| Polycystidinae | Acrorhynchides | Strand, 1928 | |
| Polycystididae | Acrorhynchidinae | Evdonin, 1977 | |
| Polycystididae | Acrorhynchina | Graff, 1882 | |
| Polycystidinae | Acrorhynchus | Graff, 1882 | |
| Alexlutheria | acrosiphoniae | Karling, 1956 | |
| Acrumeninae | Acrumena | Brunet, 1965 | |
| Cicerinidae | Acrumeninae | Karling, 1980 | |
| Notoplana | acticola | (Boone, 1929) | |
| Leptoplana | acticola | Boone, 1929 | |
| Notocomplana | acticola | (Boone, 1929) | |
| Notoplana | acticola | (Boone, 1929) | |
| Leptoplana | acticola | Boone, 1929 | |
| Actinodactylellidae | Actinodactyla | Haswell, 1893 | |
| Actinodactylellinae | Actinodactylella | Haswell, 1893 | |
| Temnocephaloidea | Actinodactylellidae | Benham, 1901 | |
| Temnocephalidae | Actinodactylellinae | Benham, 1901 | |
| Actinoposthiidae | Actinoposthia | An der Lan, 1936 | |
| Childiidae | Actinoposthia | An der Lan, 1936 | |
| Acoela | Actinoposthiidae | Hooge, 2001 | |
| Convoluta | actuosa | (Kozloff, 1965) | |
| Conaperta | actuosa | (Kozloff, 1965) | |
| Raphidophallus | actuosus | Kozloff, 1965 | |
| Aphanostoma | actuosus | (Kozloff, 1965) | |
| Axiutelga | aculeata | (Ax, 1959) | |
| Utelga | aculeata | Ax, 1959 | |
| Coelogynopora | aculeata | Ax, 1951 | |
| Cirrifera | aculeata | (Ax, 1951) | |
| Sorocelis | aculeata | Korotneff, 1912 | |
| Itaipusa | aculeata | (Ax, 1959) | |
| Odontorhynchus | aculeatus | Karling, 1956 | |
| Schizorhynchoides | aculeatus | L'Hardy, 1963 | |
| Eukalyptorhynchia | Aculeorhynchidae | Schilke, 1969 | |
| Aculeorhynchidae | Aculeorhynchus | Schilke, 1969 | |
| Childia | aculifera | Nilsson, Wallberg, & Jondelius, 2011 | |
| Obrimoposthia | acuminata | Sluys & Ball, 1989 | |
| Typhlolepta | acuminata | (Stimpson, 1857) | |
| Typhlocolax | acuminata | Stimpson, 1857 | |
| Haplodiscus | acuminatus | Bohmig, 1895 | |
| Xenotoplana | acus | Ax, Weidemann & Ehlers, 1978 | |
| Macrostomum | acus | Wang, 2005 | |
| (Castrada) | acuta | Braun, 1885 | |
| Serrulina | acuta | (Schockaert, Curini-Galletti, De Ridder, Volonterio, & Artois, 2009) | |
| Leptoplana | acuta | Stimpson, 1855 | |
| Leptoplana | acuta | Stimpson, 1855 | |
| Rogneda | acuta | Brunet, 1979 | |
| Tajikacelis | acuta | Curini-Galletti & Schockaert, 2021 | |
| Typhlolepta | acuta | Girard, 1854 | |
| Typhlocolax | acuta | (Girard, 1854) | |
| Serrula | acuta | Schockaert, Curini-Galletti, De Ridder, Volonterio, & Artois, 2009 | |
| Macrostomum | acutum | Ax, 2008 | |
| Brachyrhynchus | acutus | Artois & Schockaert, 2013 | |
| Elasmodes | acutus | (Stimpson, 1855) | |
| Brachyrhynchoides | acutus | (Artois & Schockaert, 2013) | |
| Australopacifica | adae | (Dendy, 1891) | |
| Geoplana | adae | Dendy, 1891 | |
| Lenkunya | adae | (Dendy, 1891) | |
| Convoluta | adaica | Beklemisch, 1964 | |
| Geoplana | fletcheri | adelaidensis | Dendy, 1892 |
| Artioposthia | adelaidensis | (Dendy, 1892) | |
| Childiidae | Adeloposthia | An der Lan, 1936 | |
| Haploposthiidae | Adenocauda | Dörjes, 1968 | |
| Proporidae | Adenocauda | Dörjes, 1968 | |
| Protoplanellinae | Adenocerca | Reisinger, 1924 | |
| Cryptocelididae | Adenodactyloplana | Bulnes, Faubel, & Ponce de Leon, 2003 | |
| Neodendrocoelum | adenodactylosum | (Stankovic & Komarek, 1927) | |
| Dendrocoelum | adenodactylosum | (Stankovic & Komarek, 1927) | |
| Philactinoposthia | adenogonaria | Dörjes, 1968 | |
| Convolutidae | Adenopea | Antonius, 1968 | |
| Solenopharynginae | Adenopharynx | Ehlers, 1972 | |
| Discocelidae | Adenoplana | Stummer-Traunfels, 1933 | |
| Discocelididae | Adenoplana | Stummer-Traunfels, 1933 | |
| Typhloplaninae | Adenoplea | Reisinger, 1924 | |
| Thalassotyphloplanida | Adenorhynchidae | Ax & Heller, 1970 | |
| Promesostomidae | Adenorhynchinae | Ax & Heller, 1970 | |
| Adenorhynchidae | Adenorhynchus | Meixner, 1938 | |
| Bipalium | adensameri | Graff, 1899 | |
| Phaenocora | adenticulata | Gilbert, 1938 | |
| Euprosthiostomum | adhaerens | Bock, 1925 | |
| Euprosthiostomum | adhaerens | Bock, 1925 | |
| Acentrosomata | Adiaphanida | Noren & Jondelius, 2002 | |
| Adinoplanini | Adinoplana | Almeida & Carbayo, 2022 | |
| Geoplaninae | Adinoplanini | Almeida & Carbayo, 2022 | |
| Bipalium | admarginatum | de Beauchamp, 1933 | |
| Djeziraia | adriani | Diez, Sanjuan, Monnens, & Artois, 2023 | |
| Pogaina | adriatica | (Dörler, 1900) | |
| Vejdovskya | adriatica | (Dörler, 1900) | |
| Vortex | adriatica | Dörler, 1900 | |
| Schultzia | adriatica | (Dörler, 1900) | |
| Annulorhynchus | adriaticus | Karling, 1956 | |
| Dugesia | adunca | Chen & Sluys, 2022 | |
| Bipalium | adventitium | Hyman, 1943 | |
| Marionfyfea | adventor | Jones & Sluys, 2016 | |
| Hallangiidae | Aechmalotus | Beklemischev, 1915 | |
| Pseudodiscocelis | aegeanensis | Bulnes, 2010 | |
| Thalassotyphloplanida | Aegira | Willems, Artois, Vermin, Backeljau, & Schockaert, 2005 | |
| Philosyrtis | aegusae | Lanfranchi, Melai & Meini, 2011 | |
| Convoluta | aegyptica | Antonius, 1968 | |
| Cryptophallus | aegypticus | Melouk, 1940 | |
| Cryptophallus | aegypticus | Melouk, 1940 | |
| Trigonoporus | aegypticus | (Melouk, 1940) | |
| Macrostomum | aegyptium | Beltagi, 1972 | |
| Dugesia | aenigma | De Vries, 1984 | |
| Myozona | aerumnosa | Sopott-Ehlers & Schmidt, 1974 | |
| Aulopharynx | aestuarius | Ehlers, 1972 | |
| Invenusta | aestus | Sopott-Ehlers, 1976 | |
| Dugesia | aethiopica | Stocchino, Corso, Manconi, & Pala, 2002 | |
| Syndesmis | aethopharynx | Westervelt & Kozloff, 1990 | |
| Pseudogeoplana | aevipandemiae | Lago-Barcia & Carbayo, 2021 | |
| Kawanabella | afanasyevae | Timoshkin, 2004 | |
| Dendrocoelum | affine | Codreanu & Balcesco, 1970 | |
| Prosthiostomum | affine | Stimpson, 1857 | |
| Polycladodes | affine | (Codreanu & Balcesco, 1970) | |
| Prosthiostomum | affine | Stimpson, 1857 | |
| Eurylepta | affinis | Collingwood, 1876 | |
| Planaria | affinis | Ørsted, 1843 | |
| Pseudoceros | affinis | (Kelaart, 1858) | |
| Stylochoplana | affinis | Palombi, 1940 | |
| Pseudoceros | affinis | (Collingwood, 1876) | |
| Proxenetes | affinis | (Jensen, 1878) | |
| Provortex | affinis | (Jensen, 1878) | |
| Vortex | affinis | Jensen, 1878 | |
| Polyposthides | affinis | Palombi, 1923 | |
| Eurylepta | affinis | Collingwood, 1876 | |
| Foviella | affinis | (Ørsted, 1843) | |
| Stylochoplana | affinis | Palombi, 1940 | |
| (Castrada) | affinis | Hofsten N, 1907 | |
| Fovia | affinis | (Ørsted, 1843) | |
| Armatoplana | affinis | (Palombi, 1940) | |
| Leptoplana | affinis | Stimpson, 1857 | |
| Leptoplana | affinis | (Stimpson, 1857) | |
| Polyposthides | affinis | Palombi, 1923 | |
| Mesostoma | africanum | Kolasa, 1976 | |
| Othelosoma | africanum | (Graff, 1899) | |
| Artiocotylus | africanus | (Graff, 1899) | |
| Platydemus | africanus | Graff, 1899 | |
| Catenulidae | Africatenula | Young, 1976 | |
| Dugesia | afromontana | Stocchino & Sluys, 2012 | |
| Proporidae | Afronta | Hyman, 1944 | |
| Haploposthiidae | Afronta | Hyman, 1944 | |
| Microstomum | afzelii | Atherton & Jondelius, 2019 | |
| Phaenocora | agassizi | Graff, 1911 | |
| Pseudoceros | agattiensis | Dixit, 2019 | |
| Spathula | agelaea | Hay & Ball, 1979 | |
| Mesostomum | agile | Levinsen, 1879 | |
| Archaphanostoma | agile | (Jensen, 1878) | |
| Baltalimania | agile | (Jensen, 1878) | |
| Bolbodendrocoelum | agile | de Beauchamp, 1932 | |
| Mecynostomum | agile | Jensen, 1878 | |
| Dendrocoelum | agile | de Beauchamp, 1932 | |
| Stenostomum | agile | Silliman, 1885 | |
| Promesostoma | agile | (Levinsen, 1879) | |
| Monocelis | agilis | Schultze, 1851 | |
| (Castrella) | agilis | Fuhrmann, 1900 | |
| Euplanaria | agilis | (Stringer, 1909) | |
| Haplodiscus | agilis | Beklemischev, 1927 | |
| Dugesia | agilis | (Stringer, 1909) | |
| Stylochoplana | agilis | Lang, 1884 | |
| Pocillorhynchus | agilis | Brunet, 1973 | |
| Monotus | agilis | Graff L, 1882 | |
| Comoplana | agilis | (Lang, 1884) | |
| Rogneda | agilis | Uljanin, 1870 | |
| Maehrenthalia | agilis | (Levinsen, 1879) | |
| Planaria | agilis | Stringer, 1909 | |
| Stylochoplana | agilis | Lang, 1884 | |
| (Castrada) | agilis | Dorner, 1902 | |
| Jensenia | agilis | (Fuhrmann, 1900) | |
| Kambanella | agilis | Steinböck, 1931 | |
| Convoluta | agilis | An der Lan, 1936 | |
| Pseudomonocelis | agilis | (Schultze, 1851) | |
| Monops | agilis (1) | (Schultze, 1851) | |
| Monops | agilis (2) | Diesing, 1862 | |
| Phaenocora | aglobulata | Houben & Artois, 2015 | |
| Geoplana | agricola | Dendy, 1894 | |
| Newzealandia | agricola | (Dendy, 1894) | |
| Choeradoplana | agua | Carbayo, Silva, Riutort & Alvarez-Presas, 2017 | |
| Pseudostylochus | aino | Kato, 1937 | |
| Pseudostylochus | aino | Kato, 1937 | |
| Microplana | aixandrei | Vila-Farre, Mateos, Sluys, & Romero, 2008 | |
| Mesostoma | ajpetri | Nasonov, 1924 | |
| Plagiostomidae | Akamptostoma | Riedl, 1959 | |
| Seidlia | akkeshi | (Ichikawa & Kawakatsu, 1963) | |
| Polycelis | akkeshi | Ichikawa & Kawakatsu, 1963 | |
| Ommatoplana | akkeshiensis | (Kato, 1937) | |
| Microstylochus | akkeshiensis | Kato, 1937 | |
| Mirostylochus | akkeshiensis | Kato, 1937 | |
| Mirostylochus | akkeshiensis | Kato, 1937 | |
| Sphalloplana | alabamensis | Hyman, 1945 | |
| Pseudodalyellia | alabamensis | Van Steenkiste, Gobert & Artois, 2011 | |
| Paraproboscifer | alacerregis | De Clerck, 1994 | |
| Bothrioplana | alacris | Sekera, 1889 | |
| Thysanozoon | alagoensis | Bahia, Padula, Correia, & Sovierzoski, 2015 | |
| Dendrocoelidae | Alaoplana | Kenk, 1974 | |
| Ptychopera | alaskana | Ax & Armonies, 1990 | |
| Pogaina | alaskana | Ax & Armonies, 1990 | |
| Promesostoma | alaskanum | Ax & Armonies, 1990 | |
| Otoplaninae | Alaskaplana | Ax & Armonies, 1990 | |
| Dendrocoelopsis | alaskensis | Kenk, 1953 | |
| Coelogynopora | alata | Tajika, 1981 | |
| Microstomidae | Alauretta | Mereschkowsky, 1878 | |
| Microstomidae | Alaurina | Busch, 1851 | |
| Eurylepta | alba | (Freeman, 1933) | |
| Australoplana | alba | (Dendy, 1891) | |
| Caenoplana | alba | (Dendy, 1891) | |
| Leptoplana | alba | (Kelaart, 1858) | |
| Planaria | alpina | alba | Oye, 1935 |
| Crenobia | alpina | alba | (Oye, 1935) |
| Cryptocelis | alba | (Schmidtlein, 1880) | |
| Alaurina | alba | Attems, 1897 | |
| Cryptocelis | alba | Lang, 1884 | |
| Spathula | alba | Allison, 1997 | |
| Australoplana | sanguinea | alba | (Dendy, 1891) |
| Dalyellia | alba | Higley, 1918 | |
| Marcusia | alba | Cuadrado, Rodriguez, Moro, Grande, & Noreña, 2021 | |
| Dendrocoelum | alba | (Linné, 1746) | |
| Temnosewellia | alba | Sewell, Cannon & Blair, 2006 | |
| Penula | alba | Kelaart, 1858 | |
| Leptoplana | alba | Lang, 1880 | |
| Friedmaniella | alba | Timoshkin, 1985 | |
| Monocelis | alba | Levinsen, 1879 | |
| Caenoplana | sanguinea | alba | Dendy 1891 |
| Australopacifica | sanguinea | alba | Dendy, 1891 |
| Coleophora | alba | (Levinsen, 1879) | |
| Polycladodes | alba | Steinmann, 1910 | |
| Leptoplana | alba | Kelaart, 1858 | |
| Geoplana | sanguinea | alba | Dendy, 1892 |
| Sorocelis | alba | Sabussow, 1903 | |
| Pericelis | alba | (Cuadrado, Rodriguez, Moro, Grande, & Noreña, 2021) | |
| Ascidiophilla | alba | Newman, 2002 | |
| Geoplana | alba | Dendy, 1891 | |
| Acerotisa | alba | (Freeman, 1933) | |
| Minona | alba | Levinsen, 1879 | |
| (Castrella) | alba | Luther, 1955 | |
| Leptoplana | alba | Schmidtlein, 1880 | |
| Penecurva | albata | Ichikawa & Kawakatsu, 1962 | |
| Temnosewellia | albata | Sewell, Cannon & Blair, 2006 | |
| Phagocata | albata | (Ichikawa & Kawakatsu, 1962) | |
| Crassiplana | albatrossi | Hyman, 1955 | |
| Crassiplana | albatrossi | Hyman, 1955 | |
| Polycystidinae | Albertorhynchus | Schockaert, 1976 | |
| Baicalellia | albicauda | Nasonov, 1930 | |
| Pasipha | albicaudata | Amaral & Leal-Zanchet, 2018 | |
| Convoluta | albicincta | Schultze, 1851 | |
| Anisorhynchodemus | albicinctus | (Graff, 1899) | |
| Platydemus | albicinctus | Graff, 1899 | |
| Prostheceraeus | albicinctus | Lang, 1884 | |
| Monotus | albicinctus | (Schultze, 1849) | |
| Orthodemus | albicollis | (Graff, 1899) | |
| Microplana | albicollis | (Graff, 1899) | |
| Rhynchodemus | albicollis | Graff, 1899 | |
| Prostheceraeus | albicornis | (Stimpson, 1857) | |
| Pseudoceros | albicornis | (Stimpson, 1857) | |
| Pseudoceros | albicornus | (Stimpson, 1857) | |
| Proceros | albicornus | Stimpson, 1857 | |
| Prostheceraeus | albicornus | (Stimpson, 1857) | |
| Pseudoceros | albicuneatus | Prudhoe, 1989 | |
| Syndesmis | albida | Kozloff & Westervelt, 1990 | |
| Dendrocoelum | albidum | Kenk, 1978 | |
| Arthurdendyus | albidus | Jones & Gerard, 1999 | |
| Olisthanella | albiensis | Sekera, 1912 | |
| Sorocelis | albifrons | Korotneff, 1910 | |
| Pseudoceros | albimaculatus | Prudhoe, 1989 | |
| Planariidae | Albioplanaria | Kawakatsu, 1966 | |
| Planariidae | Albiplanaria | Komarek, 1926 | |
| Pseudoceros | albireticulatus | Prudhoe, 1989 | |
| Fonticola | albissima | (Vejdovsky, 1883) | |
| Albiplanaria | albissima | (Vejdovsky, 1883) | |
| Phagocata | albissima | (Vejdovsky, 1883) | |
| Planaria | albissima | Vejdovsky, 1883 | |
| Haploposthia | albiventer | Marcus, 1954 | |
| Kuma | albiventer | (Marcus, 1954) | |
| Bipalium | albo-coeruleus | (Bleeker, 1844) | |
| Sphyrocephalus | albo-coeruleus | Bleeker, 1844 | |
| Minona | albocincta | Curini-Galletti, 1997 | |
| Prostheceraeus | albocinctus | Lang, 1884 | |
| Cycloporus | albofasciatus | Newman & Cannon, 2002 | |
| Monocelis | alboguttata | Curini-Galletti, 1991 | |
| Dugesia | montana | albolineata | Nurse, 1950 |
| Australopacifica | albolineata | (Steel, 1897) | |
| Girardia | festai | albolineata | (Borelli, 1898) |
| Dugesia | festae | albolineata | Borelli, 1898 |
| Geoplana | albolineata | Steel, 1897 | |
| festae | albolineata | Borelli, 1898 | |
| Caenoplana | albolineata | (Steel, 1897) | |
| Darwinia | albomaculata | Pereyaslawzewa, 1892 | |
| Convoluta | albomaculata | (Pereyaslawzewa, 1892) | |
| Armatoplana | albomaculata | Oya, Tsuyuki, & Kajihara, 2022 | |
| Pseudoceros | albomarginatus | Hyman, 1959 | |
| Pseudoceros | albomarginitus | Hyman, 1959 | |
| Geoplana | albonigra | (Riester, 1938) | |
| Notogynaphallia | albonigra | (Riester, 1938) | |
| Choeradoplana | albonigra | (Riester, 1938) | |
| Acanthozoon | albopapillosum | Hyman, 1959 | |
| Acanthozoon | albopapillosus | Hyman, 1959 | |
| Pseudogeoplana | albopunctata | (Graff, 1899) | |
| Geoplana | albopunctata | Graff, 1899 | |
| Acanthozoon | albopunctatum | Prudhoe, 1978 | |
| Acanthozoon | albopunctatus | Prudhoe, 1978 | |
| Neodendrocoelum | album | Komarek, 1953 | |
| Trigonostomum | setigerum | album | Graff, 1905 |
| Plagiostomum | album | Hyman, 1938 | |
| Allostoma | album | (Levinsen, 1879) | |
| Macrostomum | album | Higley, 1918 | |
| Cylindrostoma | album | Levinsen, 1879 | |
| Microstomum | album | (Attems, 1897) | |
| Aphanostoma | album | Dörjes, 1968 | |
| Dendrocoelum | album | (Steinmann, 1910) | |
| Monotus | albus | (Levinsen, 1879) | |
| Stylochoides | albus | Hallez, 1905 | |
| Oligocladus | albus | Freeman, 1933 | |
| Stylochoides | albus | (Hallez, 1905) | |
| Stylochus | albus | Hallez, 1905 | |
| Stylochus | albus | Hallez, 1905 | |
| Gyrator | albus | Silliman, 1885 | |
| Oligocladus | albus | Freeman, 1933 | |
| Syndesmis | alcalai | Komschlies & Vande-Vusse, 1980 | |
| Notoplanides | alcha | Marcus & Marcus, 1968 | |
| Polycystidinae | Alcha | Marcus, 1949 | |
| Stylochoplana | alcha | (Marcus & Marcus, 1968) | |
| Notoplanides | alcha | Marcus & Marcus, 1968 | |
| Alchoides | alchoides | Willems, Schockaert, Artois 2006 | |
| Polycystididae | Alchoides | Willems, Schockaert, Artois 2006 | |
| Notoplana | alcinoi | (Schmidt, 1861) | |
| Notoplana | alcinoi | (Schmidt, 1862) | |
| Leptoplana | alcinoi | Schmidt, 1862 | |
| Leptoplana | alcinoi | Schmidt, 1861 | |
| Thysanozoon | alderi | Collingwood, 1876 | |
| Acanthozoon | alderi | (Collingwood, 1876) | |
| Thysanozoon | alderi | Collingwood, 1876 | |
| Opisthocystis | aleksandri | Timoshkin, Zaytseva & Gutsol, 2009 | |
| Adinoplana | alerna | Almeida & Carbayo, 2022 | |
| Dendrocoelum | alexandrinae | Codreanu & Balcesco, 1970 | |
| Paradendrocoelum | alexandrinae | (Codreanu & Balcesco, 1970) | |
| Stylochus | alexandrinus | Steinbock, 1937 | |
| Stylochus | alexandrinus | Steinböck, 1937 | |
| Jenseniidae | Alexlutheria | Karling, 1956 | |
| Artioposthia | alfordensis | (Dendy, 1896) | |
| Geoplana | alfordensis | Dendy, 1896 | |
| Australopacifica | alfordensis | (Dendy, 1896) | |
| Proschizorhynchus | algarvensis | Gobert, Monnens, Eerdekens, Schockaert, Reygel, & Artois, 2020 | |
| Vaillantiella | algerica | Luther, 1955 | |
| Monocelis | algicola | Curini-Galletti & Casu, 2016 | |
| Polycystis | ali | Schockaert, 1982 | |
| Eurylepta | alicula | Pitale & Apte, 2021 | |
| Catenula | alitha | Marcus, 1945 | |
| Obama | allandra | Marques, Rossi, Valiati & Leal-Zanchet, 2018 | |
| Latocestidae | Alleena | Marcus, 1947 | |
| Latocestinae | Alleena | Marcus, 1947 | |
| Lehardyia | alleithoros | Whitson, Smith & Litvaitis, 2011 | |
| Thysanozoon | allmani | Collingwood, 1876 | |
| Acanthozoon | allmani | (Collingwood, 1876) | |
| Thysanozoon | allmani | Collingwood, 1876 | |
| Neoophora | Alloeocoela | Graff, 1882 | |
| Plagiostomidae | Alloeopharynx | Steinböck, 1932 | |
| Unguiphora | Alloeostyliphora | Curini-Galletti, Oggiano, & Casu 2001 | |
| Uteriporinae | Allogenus | Sluys, 1989 | |
| Neoophora | Alloiocoela | Graff, 1882 | |
| Stylochoplaninae | Alloioplana | Plehn, 1896 | |
| Stylochoplanidae | Alloioplana | Plehn, 1896 | |
| Plagiostomidae | Allopharynx | Steinböck, 1932 | |
| Pseudostomidae | Allostoma | Beneden, 1861 | |
| Cylindrostomidae | Allostoma | Beneden, 1861 | |
| Prolecithophora | Allostomidae | Graff, 1882 | |
| Cylindrostomidae | Allostominae | Graff, 1882 | |
| Cylindrostomidae | Allostomum | Beneden, 1861 in Mack-Fira (1974) | |
| Actinoposthiidae | Alluna | Faubel & Regier, 1983 | |
| Isodiametridae | Alluna | Faubel & Regier, 1983 | |
| Convolutidae | Alluna | Faubel & Regier, 1983 | |
| Polycelis | alma-atina | Zabusova, 1947 | |
| Polycelis | sabussowi | almaatina | (Zabusova, 1947) |
| Seidlia | sabussowi | almaatina | Porfirieva, 1960 |
| Seidlia | almaatina | Zabusova, 1947 | |
| Planaria | alpina | (Dana, 1766) | |
| Temnohaswellia | alpina | Sewell, Cannon & Blair, 2006 | |
| Crenobia | alpina | alpina | (Dana, 1766) |
| Crenobia | alpina | (Dana, 1766) | |
| Fasciola | alpina | (Dana, 1766) | |
| Dugesia | alpina | (Dana, 1766) | |
| Prorhynchus | alpinus | Steinböck, 1924 | |
| Fonticola | altaica | Livanov & Zabusova, 1940 | |
| Polycelis | tenuis | altaica | Livanov & Zabusova, 1940 |
| Phagocata | altaica | (Livanov & Zabusova, 1940) | |
| Ijimia | tenuis | altaica | Livanov & Zabusova, 1940 |
| Geoplana | alterfusca | Hyman, 1962 | |
| Novibipalium | alterifuscatum | Kawakatsu, Ogren & Froehlich, 1998 | |
| Bipaliinae | Bipalium | alternans | de Beauchamp, 1930 |
| Bipalium | penzigi | alternans | de Beauchamp, 1930 |
| Phaenocora | alticola | Ruebush, 1939 | |
| Eumecynostomum | altitudi | Faubel & Regier, 1983 | |
| Plagiostomidae | Alvaera | Bock, 1923 | |
| Geoplanini | Amaga | Ogren & Kawakatsu, 1990 | |
| Amaga | amagensis | (Fuhrmann, 1914) | |
| Geoplana | amagensis | Fuhrmann, 1914 | |
| Rogneda | amai | (Schockaert, 1976) | |
| Albertorhynchus | amai | Schockaert, 1976 | |
| Cryptocelis | amakusaensis | Kato, 1936 | |
| Cryptocelis | amakusaensis | Kato, 1936 | |
| Prosthiostomidae | Amakusaplana | Kato, 1938 | |
| Prosthiostomidae | Amakusaplana | Kato, 1938 | |
| Macrostomum | amaniense | Young, 1976 | |
| Limnostylochus | amara | (Kaburaki, 1918) | |
| Planaria | amara | Fox, 1927 | |
| Limnostylochus | amara | (Kaburaki, 1918) | |
| Shelfordia | amara | Kaburaki, 1918 | |
| Shelfordia | amara | Kaburaki, 1918 | |
| Limnoplana | amara | (Kaburaki, 1918) | |
| Haplogonaria | amarilla | Hooge & Eppinger, 2005 | |
| Temnocephala | amatoi | Seixas & Amato, 2020 | |
| Planaria | ambigua | Böhmig, 1902 | |
| Curtisia | ambigua | (Bohmig, 1902) | |
| Dugesia | ambigua | Bohmig, 1902 | |
| Pseudocerotidae | Amblyceraeus | Plehn, 1898 | |
| Pseudocerotidae | Amblyceraeus | Plehn, 1897 | |
| Microplaninae | Amblyplana | Graff, 1896 | |
| Anisorhynchodemus | amboinensis | (Graff, 1899) | |
| Rhynchodemus | amboinensis | Graff, 1899 | |
| Carcharodorhynchus | ambronensis | Schilke, 1970 | |
| Thylacorhynchus | ambronensis | Schilke, 1970 | |
| Parotoplana | ambrosolii | Curini-Galletti & Delogu, 2014 | |
| Cryptocelidinae | Amemiyaia | Kato, 1944 | |
| Cryptocelidinae | Amemiyaia | Kato, 1944 | |
| Myozonaria | americana | Rieger, 1971 | |
| Sorocelis | americana | Hyman, 1939 | |
| Maehrenthalia | americana | Ax & Armonies, 1990 | |
| Vannuccia | tripapillosa | americana | Ax & Sopott-Ehlers, 1979 |
| Dendrocoelopsis | americana | (Hyman, 1939) | |
| Digynopora | americana | Hyman, 1940 | |
| Digynopora | americana | Hyman, 1940 | |
| Otoplaninae | Americanaplana | Ax & Ax, 1967 | |
| Rhynchodemus | americanus | Hyman, 1943 | |
| Polycystididae | Ametochus | Willems, Schockaert, Artois 2006 | |
| Stylochoplana | amica | Kato, 1937 | |
| Stylochoplana | amica | Kato, 1937 | |
| Duplominona | amnica | (Ball & Hay1977) | |
| Minona | amnica | Ball & Hay, 1977 | |
| Diatomovora | amoena | Kozloff, 1965 | |
| Allostoma | amoenum | Karling, 1962 | |
| Vorticeros | cyrtum | amoma | Marcus, 1947 |
| Amphibioplanidae | Amphibioplana | Stocchino & Sluys, 2021 | |
| Cavernicola | Amphibioplanidae | Stocchino & Sluys, 2021 | |
| Planocera | amphibola | (Schmarda, 1859) | |
| Protoplanellinae | Amphibolella | Findenegg, 1924 | |
| Planocera | amphibolus | (Schmarda, 1859) | |
| Stylochus | amphibolus | Schmarda, 1859 | |
| Stylochus | amphibolus | Schmarda, 1859 | |
| Convolutidae | Amphichoerus | Graff, 1891 | |
| Kronborgia | amphipodicola | Christensen & Kanneworff, 1964 | |
| Schizorhynchidae | Amphirhynchus | Schilke, 1970 | |
| Convolutidae | Amphiscolops | Graff, 1904 | |
| Convolutidae | Amphiscolopus | Kato, 1957 | |
| Stenostomum | amphotum | Marcus, 1945 | |
| Trepaxonemata | Amplimatricata | Egger, Lapraz, Tomiczek, et al., 2015 | |
| Dendrocoelum | amplum | Harrath & Sluys, 2012 | |
| Asilomaria | ampullata | Karling, 1966 | |
| (Paraxenetes) | ampullatus | Ax, 1971 | |
| Proxenetes | ampullatus | Ax, 1971 | |
| Prosthiostomum | amri | Rodriguez, Hutchings & Williamson, 2021 | |
| Macrostomum | amurense | Beklemischev, 1950 | |
| Dendrocoelidae | Amyadenium | de Beauchamp, 1931 | |
| Amyellidae | Amyella | Bock, 1922 | |
| Chromoplanidae | Amyella | Bock, 1922 | |
| Chromoplanoidea | Amyellidae | Faubel, 1984 | |
| Boninioidea | Amyellidae | Faubel, 1984 | |
| Pseudocerotoidea | Amyellidae | Faubel, 1984 | |
| Gnesiocerotidae | Amyris | Marcus & Marcus, 1968 | |
| Notoplanidae | Amyris | Marcus & Marcus, 1968 | |
| Rhynchodemus | anamallensis | de Beauchamp, 1930 | |
| Incapora | anamallensis | (de Beauchamp, 1930) | |
| Cratera | anamariae | Carbayo, 2015 | |
| Reinhardorhynchus | anamariae | Diez, Aguirre, Reygel, & Artois, 2021 | |
| Ilyplanidae | Anandroplana | Hyman, 1955 | |
| Taenioplaninae | Anandroplana | Hyman, 1955 | |
| Taenioplaninae | Anandroplana | Hyman, 1955 | |
| Acoela | Anaperidae | Dörjes, 1968 | |
| Anaperidae | Anaperus | Graff, 1911 | |
| Convolutidae | Anaperus | Graff, 1911 | |
| Anokkostenostomum | anatirostrum | (Marcus, 1945) | |
| Stenostomum | anatirostrum | Marcus, 1945 | |
| Debeauchampia | anatolica | Benazzi, 1981 | |
| Procerodes | anatolicus | (Benazzi, 1981) | |
| Dugesia | anceps | (Kenk, 1930) | |
| Euplanaria | anceps | Kenk, 1930 | |
| Girardia | anceps | (Kenk, 1930) | |
| Baicalellia | anchoragensis | Ax & Armonies, 1990 | |
| Euryleptidae | Anciliplana | Heath & McGregor, 1912 | |
| Euryleptinae | Anciliplana | Heath & McGregor, 1912 | |
| Gnathorhynchidae | Ancistrorhynchus | L'Hardy, 1963 | |
| Paulodora | ancora | Artois & Tessens, 2008 | |
| Dugesia | ancoraria | Zhu & Wang, 2024 | |
| Idioplaninae | Ancoratheca | Prudhoe, 1982 | |
| Callioplanidae | Ancoratheca | Prudhoe, 1982 | |
| Neostylochus | ancorus | Rodriguez, Hutchings & Williamson, 2021 | |
| Convolutidae | Ancyclocirrus | Kozloff, 2000 | |
| Isodiametridae | Ancylocirrus | Kozloff, 2000 | |
| Dugesia | andamanensis | (Kaburaki, 1925) | |
| Euplanaria | andamanensis | (Kaburaki, 1925) | |
| Girardia | anderlani | (Kawakatsu & Hauser, 1983) | |
| Dugesia | anderlani | Kawakatsu & Hauser 1983 | |
| Collastoma | anderseni | Roehl, 2017 | |
| Kontikia | andersoni | Jones, 1981 | |
| Synsiphonium | anderssoni | (Westblad, 1952) | |
| Siphoniella | anderssoni | Westblad, 1952 | |
| Mesostoma | andicola | (Schmarda, 1859) | |
| Pseudogeoplana | andicola | (Schmarda, 1859) | |
| Geoplana | andicola | Schmarda, 1859 | |
| Polycladus | andicola | Schmarda, 1859 | |
| Strongylostoma | andicola | Schmarda, 1859 | |
| Turbella | andicola (1) | (Schmarda, 1859) | |
| Turbella | andicola (2) | (Schmarda, 1859) | |
| Notogynaphallia | andina | (Hyman, 1962) | |
| Planaria | andina | Borelli, 1895 | |
| Girardia | andina | (Borelli, 1895) | |
| Dugesia | andina | (Borelli, 1895) | |
| Euplanaria | andina | (Borelli, 1895) | |
| Geoplana | andina | Hyman, 1962 | |
| Castradella | granea | andreja | (Nasonov, 1919) |
| (Castrada) | andreja | Nasonov, 1919 | |
| Diversibipalium | andrewsi | (Whitehouse, 1919) | |
| Mesostoma | andrewsi | Hyman, 1957 | |
| Bipalium | andrewsi | Whitehouse, 1919 | |
| Dendrocoelum | angarense | (Gerstfeldt, 1858) | |
| Planaria | angarensis | Gerstfeldt, 1858 | |
| Polycystis | angarensis | Sibiriakova, 1929 | |
| Bdellocephala | angarensis | angarensis | (Gerstfeldt, 1858) |
| Opisthocystis | angarensis | (Sibiriakowa, 1929) | |
| Bdellocephala | angarensis | (Gerstfeldt, 1858) | |
| Sorocelis | angarensis | Korotneff, 1912 | |
| Paraplanocera | angeli | Soutullo, Cuadrado & Norena, 2021 | |
| Cohenella | angelinae | Timoshkin & Krivorotkin, 2023 | |
| Rogneda | anglica | Karling, 1953 | |
| Amblyplana | notabilis | angolense | de Beauchamp, 1951 |
| Othelosoma | angolense | (de Beauchamp, 1951) | |
| Artiocotylus | notabilis | angolensis | de Beauchamp, 1951 |
| Celidotus | anguilla | (Schmidt, 1857) | |
| Monocelis | anguilla | Schmidt, 1857 | |
| Mesostoma | angulare | Higley, 1918 | |
| Jensenia | angulata | (Jensen, 1879) | |
| Fasciola | angulata | Müller, 1773 | |
| Vortex | angulatus | Jensen, 1878 | |
| Westbladiella | angulifera | Riedl, 1954 | |
| Zygantroplana | angusta | (Verrill, 1893) | |
| Phagocata | angusta | Kenk, 1977 | |
| Stylochoplana | angusta | (Verrill, 1893) | |
| Newzealandia | graffii | angusta | (Dendy, 1901) |
| Zygantroplana | angusta | (Verrill, 1893) | |
| Stylochoplana | angusta | (Verrill, 1893) | |
| Comoplana | angusta | (Verrill, 1893) | |
| Geoplana | graffii | angusta | Dendy, 1901 |
| Leptoplana | angusta | Verrill, 1893 | |
| Leptoplana | angusta (1) | Pearse, 1938 | |
| Leptoplana | angusta (2) | Pearse & Littler, 1938 | |
| Leptoplana | angusta (3) | Pearse & Littler, 1938 | |
| Leptoplana | angusta (4) | Verrill, 1893 | |
| Castrada | stagnorum | angustibursa | Steinböck & Lanser, 1932 |
| Derostoma | angusticeps | Duges, 1830 | |
| Proschizorhynchus | angusticirrus | Armonies, 2023 | |
| Beklemischeviella | angustior | Luther, 1943 | |
| Euprosthiostomum | angustum | (Bock, 1913) | |
| Prosthiostomum | angustum | Bock, 1913 | |
| Prosthiostomum | angustum | Bock, 1913 | |
| Synsiphonium | angustum | Sluys & Ball, 1989 | |
| Rhynchodemus | angustus | (Hyman, 1941) | |
| Proxenetes | angustus | Ax, 1951 | |
| Desmorhynchus | angustus | Hyman, 1941 | |
| Rhynchodemini | Anisorhynchodemus | Kawakatsu, Froehlich, Jones, Ogren, and Sasaki, 2003 | |
| Aegira | annabellae | Willems, Artois, Vermin, Backeljau, & Schockaert, 2005 | |
| Shelfordia | annadalei | Kaburaki, 1918 | |
| Phonorhynchoidinae | Annalisella | Karling, 1978 | |
| Limnostylochus | annandalei | (Kaburaki, 1918) | |
| Dugesia | annandalei | (Kaburaki, 1918) | |
| Shelfordia | annandalei | Kaburaki, 1918 | |
| Bdellocephala | annandalei | Ijima & Kaburaki, 1916 | |
| Planaria | annandalei | Kaburaki, 1918 | |
| Limnoplana | annardalei | (Kaburaki, 1918) | |
| Limnostylochus | annardalei | (Kaburaki, 1918) | |
| Shelfordia | annardalei | Kaburaki, 1918 | |
| (Castrada) | annebergensis | Luther, 1946 | |
| Galapagetula | annikae | Reygel, Willems & Artois, 2011 | |
| Notoplana | annula | Marcus & Marcus, 1968 | |
| Notoplana | annula | Marcus & Marcus, 1968 | |
| Pogaina | annulata | Ax, 1970 | |
| Scanorhynchinae | Annulorhynchus | Karling, 1956 | |
| Provorticinae | Annulovortex | Beklemischev, 1953 | |
| Macrostomum | anocele | Riedel, 1932 | |
| Dendrocoelidae | Anocelis | Stimpson, 1857 | |
| Plagiostomum | anocelis | Brandtner, 1934 | |
| Dendrocoelidae | Anocelis | Grube, 1872 | |
| Gonostomula | anocelis | Westblad, 1955 | |
| Ilyplanoidea | Anocellidae | Quiroga, Bolanos & Litvaitis, 2006 | |
| Anocellidae | Anocellidus | Quiroga, Bolanos & Litvaitis, 2006 | |
| Stenostomidae | Anokkostenostomum | Norena, Damborenea & Brusa, 2005 | |
| Bergendalia | anomala | Laidlaw, 1903 | |
| Trigonoporus | anomala | (Laidlaw, 1903) | |
| Bergendalia | anomala | Laidlaw, 1903 | |
| Phaenocora | anomalocoela | (Haswell, 1905) | |
| incertae sedis | Anomalocoelus | Haswell, 1905 | |
| Prostheceraeus | anomalus | Haswell, 1907 | |
| Prostheceraeus | anomalus | Haswell, 1907 | |
| Anonymoidea | Anonymidae | Lang, 1884 | |
| Pseudocerotoidea | Anonymidae | Lang, 1884 | |
| Cotylea | Anonymidae | Lang, 1884 | |
| Cotylea | Anonymoidea | Dittman, Cuadrado, Aguado, Noreña, & Egger, 2019 | |
| Anonymidae | Anonymus | Lang, 1884 | |
| Anonymidae | Anonymus | Lang, 1884 | |
| Ethmorhynchus | anophtalmus | Meixner, 1938 | |
| Crenobia | anophthalma | (Mrazek, 1907) | |
| Planaria | anophthalma | Mrazek, 1907 | |
| Phaenocora | anophthalma | (Vejdovsky, 1895) | |
| Derostoma | anophthalma | Vejdovsky, 1895 | |
| Crenobia | alpina | anophthalma | (Mrazek, 1907) |
| Geoplaninae | Anophthalmoplana | Negrete, Francavilla, Damborenea, & Brusa, 2022 | |
| Stenostomum | anophthalmum | An der Lan, 1955 | |
| Proceropharynx | anophthalmus | (Meixner, 1929) | |
| Ethmorhynchus | anophthalmus | Meixner, 1938 | |
| Prognathorhynchus | anophthalmus | Meixner | |
| Solenopharynx | anophthalmus | Meixner, 1929 | |
| Proschizorhynchus | anophthalmus | L'Hardy, 1965 | |
| (Castrada) | anopla | Sibiriakova, 1929 | |
| Anoplodium | (Anoplodiella) | Bock, 1925 | |
| Umagillinae | Anoplodiera | Westblad, 1930 | |
| Umagillinae | Anoplodiopsis | Westblad, 1953 | |
| Umagillinae | Anoplodium | Schneider, 1858 | |
| Koinocystididae | Anoplorhynchus | Meixner, 1925 | |
| Anokkostenostomum | anops | (Nuttycombe & Waters, 1938) | |
| Stenostomum | anops | Nuttycombe & Waters, 1938 | |
| Catenulidae | Anortha | Leidy, 1852 | |
| Convoluta | anotica | Schmarda, 1859 | |
| incertae sedis | Anotocelis | Diesing, 1862 | |
| Monocelis | anta | Marcus, 1954 | |
| Parotoplanina | antaliformis | Curini-Galletti, 2014 | |
| Geoplana | antarctica | Dendy, 1909 | |
| Australopacifica | antarctica | (Dendy, 1909) | |
| Gnosonesima | antarctica | Reisinger, 1926 | |
| Stylostomum | antarcticum | Hallez, 1905 | |
| Stylostomum | antarcticum | Hallez, 1905 | |
| Mesostoma | antarcticum | Dreyer, 1918 | |
| Austrorhynchus | antarcticus | Artois, Vermin & Schockaert, 2000 | |
| Desmote | antarcticus | Shinn, 1987 | |
| Octopoxenus | antarcticus | Gordeev, Biserova, Zhukov & Ekimova, 2022 | |
| Solenopharyngidae | Anthopharynginae | Ehlers, 1972 | |
| Anthopharynginae | Anthopharynx | Karling, 1940 | |
| Notoplanidae | Anthoplana | Bo & Betti, 2019 | |
| Plagiostomum | anthracinum | Kulinitch, 1978 | |
| Obama | anthropophila | Amaral, Carbayo, & Leal-Zanchet, 2015 | |
| Polycystidinae | Antiboreorhynchus | Karling, 1952 | |
| Antigonariidae | Antigonaria | Dörjes, 1968 | |
| Acoela | Antigonariidae | Dörjes, 1968 | |
| Girardia | antillana | Kenk, 1941 | |
| Dugesia | antillana | Kenk, 1941 | |
| Adenoplana | antillarum | Hyman, 1955 | |
| Syndisyrinx | antillarum | (Powers, 1936) | |
| Syndesmis | antillarum | Powers, 1936 | |
| Boninia | antillarum | (Hyman, 1955) | |
| Adenoplana | antillarum | Hyman, 1955 | |
| Boninia | antillarum | (Hyman, 1955) | |
| Otoplana | antipa | An der Lan, 1964 | |
| Anthoplana | antipathellae | Bo & Betti, 2019 | |
| Conaperta | antonii | Achatz, Hooge & Tyler, 2007 | |
| Faerlea | antora | Marcus, 1952 | |
| Macrostomidae | Antromacrostomum | Faubel, 1974 | |
| Antroposthiidae | Antroposthia | Faubel, 1974 | |
| Acoela | Antroposthiidae | Faubel, 1976 | |
| Sagittiferinae | Antrosagittifera | Hooge & Tyler, 2001 | |
| Convolutidae | Antrosagittifera | Hooge & Tyler, 2001 | |
| Anzoplanini | Anzoplana | Winsor, 2006 | |
| Rhynchodeminae | Anzoplanini | Winsor 2006 | |
| Stylochus | aomori | Kato, 1937 | |
| Stylochus | aomori | Kato, 1937 | |
| Imogine | aomori | (Kato, 1937) | |
| Syndesmis | aonikenki | Brusa, Montes, Marcotegui, et al., 2017 | |
| Callioplanidae | Aotearoa | Holleman, 2007 | |
| Obrimoposthia | aparala | Sluys & De Vries, 1988 | |
| Flagellophora | apelti | Faubel & Dorjes, 1978 | |
| Geoplana | apeva | Froehlich, 1959 | |
| Obama | apeva | (Froehlich, 1959) | |
| Geoplana | aphalla | Hyman, 1941 | |
| Pasipha | aphalla | (Hyman, 1941) | |
| Convolutidae | Aphanostoma | Ørsted, 1845 | |
| Isodiametridae | Aphanostoma | Ørsted, 1845 | |
| Acoela | Aphanostomidae | Bohmig, 1895 | |
| Temnosewellia | aphyodes | Sewell, Cannon & Blair, 2006 | |
| Temnosewellia | apiculus | Sewell, Cannon & Blair, 2006 | |
| Apidioplanidae | Apidioplana | Bock, 1926 | |
| Apidioplanidae | Apidioplana | Bock, 1926 | |
| Planoceroidea | Apidioplanidae | Bock, 1926 | |
| Leptoplanoidea | Apidioplanidae | Bock, 1926 | |
| Obama | apiguara | Oliveira, Almeida & Carbayo, 2020 | |
| Apidioplana | apluda | Cannon, 1990 | |
| Dendrocoelum | apodendrocoeloideum | Dyganova, 1976 | |
| Dendrocoelidae | Apodendrocoelum | de Beauchamp, 1931 | |
| Acrochordonoposthia | apopera | Reisinger, 1924 | |
| Proxenetes | (Apoxinetes) | Ax, 1971 | |
| Turbella | appendiculata | Diesing, 1850 | |
| Planaria | appendiculata | Fabricius, 1826 | |
| Krumbachia | appendiculata | Schwank, 1980 | |
| Macrostomum | appendiculatum | Fabricius, 1826 | |
| Macrostomum | appendiculatum (1) | Beklemischev, 1951 | |
| Macrostomum | appendiculatum (2) | Beklemischev, 1915 | |
| Macrostomum | appendiculatum (3) | Beklemischev, 1922 | |
| Macrostomum | appendiculatum (4) | Beklemischev, 1915 | |
| Mesostoma | appia | Kolasa, 1984 | |
| Mesostoma | appinum | Kolasa & Schwartz, 1988 | |
| Geoplana | applanata | Graff, 1899 | |
| Geocentrophora | applanata | (Kennel, 1888) | |
| Obama | applanata | (Graff, 1899) | |
| Prorhynchus | applanatus | Kennel, 1888 | |
| Pseudobiceros | apricus | Newman & Cannon, 1994 | |
| Gnathorhynchus | aprosmeno | An der Lan, 1967 | |
| Yorknia | aprostatica | Schockaert, Curini-Galletti, De Ridder, Volonterio, & Artois, 2009 | |
| Schockaertia | aprostatica | Diez, Reygel, & Artois, 2023 | |
| Latocestinae | Aprostatum | Bock, 1913 | |
| Euplanidae | Aprostatum | Bock, 1913 | |
| Atrioplanaria | aquaebellae | Bromley, 1983 | |
| Planoceridae | Aquaplana | Hyman, 1953 | |
| Planoceridae | Aquaplana | Hyman, 1953 | |
| Stenostomum | leucops | aquariorum | Luther, 1960 |
| Dugesia | arabica | Harrath & Sluys, 2013 | |
| Hofstenia | arabiensis | Beltagi & Mandura, 1991 | |
| Acanthozoon | aranfaibo | Cuadrado, Moro & Norena, 2017 | |
| Cephaloflexa | araucariana | Carbayo & Leal-Zanchet, 2003 | |
| Ozametra | arbora | (Ozaki, 1932) | |
| Xenometra | arbora | Ozaki, 1932 | |
| Dugesia | arcadia | De Vries, 1988 | |
| Acanthopharynx | arcanus | Reisinger, 1924 | |
| Carcharodopharynx | arcanus | (Reisinger, 1924) | |
| Myozonaria | arcassonensis | Rieger, 1971 | |
| Pogaina | arcassonensis | Ehlers & Sopott-Ehlers, 1989 | |
| Promonotus | arcassonensis | Ax, 1959 | |
| Thylacorhynchus | arcassonensis | de Beauchamp, 1927 | |
| Sorocelis | arcellaris | Korotneff, 1912 | |
| Bdellocephala | arcellaris | (Korotneff, 1912) | |
| Actinoposthiidae | Archactinoposthia | Dörjes, 1968 | |
| Childiidae | Archactinoposthia | Dörjes, 1968 | |
| Isodiametridae | Archaphanostoma | Dörjes, 1968 | |
| Convolutidae | Archaphanostoma | Dörjes, 1968 | |
| Dendrocoelidae | Archicotylus | Korotneff, 1912 | |
| Archiloinae | Archilina | Ax, 1959 | |
| Archiloinae | Archiloa | de Beauchamp, 1910 | |
| Monocelididae | Archiloinae | Faubel & Rohde, 1998 | |
| Archiloinae | Archilopsis | Meixner, 1938 | |
| Macrostomidae | Archimacrostomum | Ferguson, 1954 | |
| Lithophora | Archimonocelididae | Meixner, 1938 | |
| Archimonocelididae | Archimonocelidinae | Meixner, 1938 | |
| Archimonocelidinae | Archimonocelis | Meixner, 1938 | |
| Protomonotresinae | Archimonotresis | Meixner, 1938 | |
| Dendrocoelides | archipannonicus | Gelei, 1927 | |
| Cheliplanidae | Archipelagoplana | Noldt & Hoxhold, 1984 | |
| Proporidae | Archiproporus | An der Lan, 1936 | |
| Provorticinae | Archivortex | Reisinger, 1924 | |
| Proxenetes | (Archixenetes) | Ax, 1971 | |
| Otocelididae | Archocelis | Dörjes, 1968 | |
| Opistominae | Archopistomum | An der Lan, 1939 | |
| Archotoplaninae | Archotoplana | Ax, 1956 | |
| Otoplanidae | Archotoplaninae | Ax, 1956 | |
| Leptoplana | arcta | (Quatrefage, 1845) | |
| Leptoplana | arcta | (Quatrefage, 1845) | |
| Plehnia | arctica | (Plehn, 1896) | |
| Proxenetes | arctica | Ax & Armonies, 1990 | |
| Notocaryoplana | arctica | Steinböck, 1935 | |
| Acerotisa | arctica | Hyman, 1953 | |
| (Typhloplanella) | arctica | Nasonov, 1923 | |
| Dalyellia | arctica | Nasonov, 1923 | |
| Olisthanella | arctica | Nasonov, 1923 | |
| Microdalyellia | arctica | (Nasonov, 1923) | |
| Beauchampiola | arctica | Ehlers & Franke, 1994 | |
| Acerotisa | arctica | Hyman, 1953 | |
| Typhloplanella | arctica | (Nasonov, 1923) | |
| Acelis (part) | arctica | Plehn, 1896 | |
| Plehnia | arctica | (Plehn, 1896) | |
| Mesostoma | arcticum | Hyman, 1938 | |
| Plagiostomum | arcticum | Brandtner, 1934 | |
| Nesion | arcticum | Hyman, 1956 | |
| Prosthiostomum | arctum | Quatrefages, 1845 | |
| Prosthiostomum | arctum | Quatrefage, 1845 | |
| Kataplana | arcuata | Sopott-Ehlers, 1976 | |
| Baltalimania | arcuatum | Atherton & Jondelius, 2022 | |
| Rimacephalus | arecepta | Porfirieva, 1969 | |
| Ceratopera | aremorica | (Ehlers & Sopott-Ehlers, 1989) | |
| Messoplana | aremorica | Ehlers & Sopott-Ehlers, 1989 | |
| Antigonaria | arenaria | Dörjes, 1968 | |
| Haplogonaria | arenaria | (Ax, 1959) | |
| Diascorhynchides | arenaria | Schilke, 1970 | |
| Archilopsis | arenaria | Martens, Curini-Galletti & Pucinelli, 1989 | |
| Pseudostomum | arenarium | Meixner, 1938 | |
| Mecynostomum | arenarium | Ax, 1959 | |
| Schizorhynchus | arenarius | de Beauchamp, 1927 | |
| Proxenetes | arenarius | Meixner, 1938 | |
| Gyratrix | arenarius | Evdonin, 1971 | |
| Paraschizorhynchus | arenarius | Meixner, 1938 | |
| Proschizorhynchus | arenarius | (de Beauchamp, 1927) | |
| Cryptocelis | arenicola | Hallez, 1893 | |
| Pseudograffilla | arenicola | Meixner, 1938 | |
| Geoplana | arenicola | Steel, 1900 | |
| Lenkunya | arenicola | (Steel, 1900) | |
| Cryptocelis | arenicola | Hallez, 1893 | |
| Scoliopharyngia | arenicola | Ehlers, Reise, & Armonies, 1995 | |
| Girardia | arenicola | Hellmann & Leal-Zanchet, 2018 | |
| Australopacifica | arenicola | (Steel, 1900) | |
| Haplogonaria | arenicolae | Faubel & Warwick, 2005 | |
| Dunwichia | arenosa | Faubel, Blome & Cannon, 1994 | |
| Stylochus | arenosus | Willey, 1897 | |
| Imogine | arenosus | (Willey, 1897) | |
| Stylochus | arenosus | Willey, 1897 | |
| Phagocata | arethusa | (Dalyell, 1814) | |
| Stenostomum | arevaloi | Gieysztor, 1931 | |
| Temnosewellia | arga | Sewell, Cannon & Blair, 2006 | |
| Argaplanini | Argaplana | Winsor, 2011 | |
| Rhynchodeminae | Argaplanini | Winsor, 2011 | |
| Supramontana | argentina | Negrete, Leal-Zanchet & Brusa, 2014 | |
| Temnosewellia | argeta | Sewell, Cannon & Blair, 2006 | |
| Temnosewellia | argilla | Sewell, Cannon & Blair, 2006 | |
| Einarella | argillophila | Luther, 1948 | |
| Sorocelis | argillosa | Korotneff, 1912 | |
| Obama | argus | (Graff, 1899) | |
| Eurylepta | argus | (Quatrefage, 1845) | |
| Eurylepta | argus | (Quatrefage, 1845) | |
| Latocestus | argus | Laidlaw, 1903 | |
| Latocestus | argus | Laidlaw, 1903 | |
| Stylochus | argus | Czerniavsky, 1981 | |
| Proceros | argus | Quatrefage, 1845 |
900 names, including those in new combination. (Max listing set to 900)