Gyraulus tetracarinatus (P.S. Pavlovic, 1903)
Biomphalaria thermali (W.A. Biese, 1951)
Anisus thermochukchensis L.A. Prozorova& Y.I. Starobogatov, 1997
Planorbarius thiollieri (FOSSIL) (A. Michaud, 1855 †)
Gundlachia ticaga (Er. Marcus & Ev. Marcus,1962)
Gyraulus tokyoensis A. Mori, 1938
Ferrissia toroensis G. Mandahl-Barth, 1954
Gyraulus transsylvanicus (M. von Neumayr, 1875 )
Ancylastrum transvaalensis A. Craven, 1880
Bulinus transversalis E.C. Von Martens, 1897
Burnupia trapezoidea (O. Böttger, 1910)
Gyraulus trapezoides W. Polinski, 1929
Planorbella traski H.C. Lea, 1856
Bulinus trigonus E.C. Von Martens, 1892
Gyraulus triquetrus (F.M. Hilgendorf, 1867 )
Helisoma trivolis T. Say
Planorbella trivolvis (T. Say, 1817)
Gyraulus trochiformis (Stahl, 1824 )
Segmentina trochoidea W.H. Benson, 1836
Bulinus trojanus (FOSSIL) (M. von Neumayr, 1883 †)
Gyraulus trolli (Sauerzopf, 1953 )
Bulinus tropicus C.F.F. von Krauss, 1848
Ferrissia truci (FOSSIL) Wautier, 1975 †
Planorbella truncata M. Miles, 1861
Planorbis truncatocarinatus (FOSSIL) P.S. Pavlovic, 1931 †
Bulinus truncatus (J.V. Audouin, 1827)
Bulinus truncatus coulboisi J.R. Bourguignat, 1888
Biomphalaria trygira (R.A. Philippi, 1869)
Vorticifex tryoni F.B. Meek
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
Menetus uliginosus (E.G. Vanatta, 1910)
Hippeutis umbilicalis W.H. Benson, 1855