Gyraulus tetracarinatus (P.S. Pavlovic, 1903)
Biomphalaria thermali (W.A. Biese, 1951)
Anisus thermochukchensis L.A. Prozorova& Y.I. Starobogatov, 1997 Kamchatka
Planorbarius thiollieri (FOSSIL) (A. Michaud, 1855 †)
Gundlachia ticaga (Er. Marcus& Ev. Marcus, 1962)
Gyraulus tokyoensis A. Mori, 1938 Japan, Gunma Pref
Ferrissia toroensis G. Mandahl-Barth, 1954 Uganda
Gyraulus transsylvanicus (M. von Neumayr, 1875 )
Ancylastrum transvaalensis A. Craven, 1880 Congo, Pointe Noire
Bulinus transversalis E.C. Von Martens, 1897 Lake Victoria
Burnupia trapezoidea (O. Böttger, 1910) Botswana
Gyraulus trapezoides W. Polinski, 1929 Macedonia
Planorbella traski H.C. Lea, 1856 USA, California
Bulinus trigonus E.C. Von Martens, 1892 Lake Victoria
Gyraulus triquetrus (F.M. Hilgendorf, 1867 )
Helisoma trivolis T. Say Michigan, Clinton County, Park Lake
Planorbella trivolvis (T. Say, 1817) Belgium18,2 mm
Gyraulus trochiformis (Stahl, 1824 )
Segmentina trochoidea W.H. Benson, 1836 Nepal2,8 mm
Bulinus trojanus (FOSSIL) (M. von Neumayr, 1883 †)
Gyraulus trolli (Sauerzopf, 1953 )
Bulinus tropicus C.F.F. von Krauss, 1848 South Africa, Durban9 mm
Ferrissia truci (FOSSIL) Wautier, 1975 † France, Rhône-Alpes
Planorbella truncata M. Miles, 1861 Wisconsin27 mm
Planorbis truncatocarinatus (FOSSIL) P.S. Pavlovic, 1931 †
Bulinus truncatus (J.V. Audouin, 1827) Algeria
Bulinus truncatus coulboisi J.R. Bourguignat, 1888 Saudi Arabia7 mm
Biomphalaria trygira (R.A. Philippi, 1869)
Vorticifex tryoni F.B. Meek North America
Anisus tugurensis L.A. Prozorova& Y.I. Starobogatov, 1997
Gyraulus turislavicus E. Jekelius, 1944
Planorbarius turkovici (FOSSIL) (Gorjanovic-Kramberger, 1899 †)
Bulinus ugandae G. Mandahl-Barth, 1954 Uganda
Menetus uliginosus (E.G. Vanatta, 1910)
Hippeutis umbilicalis W.H. Benson, 1855 Thailand, Lake Phayao