Fadyenia stevensiana E. Chitty, 1857
Fadyenia stokesiana E. Chitty, 1857
Orobophana stokesii M.C. Neal, 1934
Alcadia striata (J.B.P.A. Lamarck, 1822)
Fadyenia stricklandiana E. Chitty, 1857
Helicina subdepressa F. Poey, 1854
Helicina subfusca K.T. Menke
Helicina subglobulosa F. Poey, 1852
Emoda submarginata (J.E. Gray, 1824)
Helicina subrufa A. Garrett, 1884
Pleuropoma subsculpta M.C. Neal, 1934
Succincta succincta (E.C. Von Martens, 1890)
Alcadia succinea (L. Pfeiffer)
Pleuropoma sulculosa C.M.F. Ancey, 1904
Geophorus sulphureus J.T. Kuroda & T. Kano,1941
Aphanoconia suturalis (E.C. Von Martens, 1864)
Fadyenia swiftiana E. Chitty, 1857
Helicina sylvatica D'Orbigny, 1837
Helicina syngenes H.B. Preston, 1914
Orobophana tahitensis (W.H. Pease, 1870)
Gemma talamancensis (I. Richling, 2001)
Pleuropoma talusata J. Stanisic, 2010
Helicina tamsiana (L. Pfeiffer, 1850)
Eutrochatella tankervillii (J.E. Gray, 1824)
Geophorus tantalus P. Bartsch, 1918
Lucidella tantilla H.A. Pilsbry, 1902
Fadyenia tappaniana (C.B. Adams, 1851)
Fadyenia tayloriana E. Chitty, 1857
Tristramia tenuis (L. Pfeiffer, 1849)
Gemma terryae H.A. Rehder, 1940
Pleuropoma theobaldiana (G. Nevill & H. Nevill,1878)
Alcadia tibai T. Habe, 1976
Helicina tilei L. Pfeiffer, 1847
Emoda torrei J. Henderson, 1909
Priotrochatella torrei (W.F. Clapp, 1918)