Vespericola scotti P.A. Cordero & W.B. Miller,1995
Polygyra septemvolva T. Say, 1818
Polygyra septemvolva volvoxis L. Pfeiffer, 1846
Vespericola shasta (S.S. Berry, 1921)
Vespericola sierranus (S.S. Berry, 1921)
Stenotrema simile F.W. Grimm, 1971
Millerelix simpsoni (H.A. Pilsbry& J.H. Ferriss, 1907)
Inflectarius smithi (W.F. Clapp, 1905)
Triodopsis soelneri J. Henderson, 1907
Neohelix solemi K.C. Emberton, 1988
Stenotrema spinosum H.C. Lea, 1830
Ashmunella sprouli W. Fullington & W. Fullington,
Stenotrema stenotrema L. Pfeiffer, 1842
Upsilodon sterni A. Metcalf & D.H. Riskind,1978
Praticolella strebeliana H.A. Pilsbry, 1899
Daedalochila subclausa H.A. Pilsbry, 1899
Inflectarius subpalliatus (H.A. Pilsbry, 1893)
Triodopsis subpersonatum (A.T. von Middendorff,1851)
Linisia suprazonata (H.A. Pilsbry, 1899)
Praticolella taeniata H.A. Pilsbry, 1940
Linisia tamaulipasensis (H.C. Lea, 1857)
Trilobopsis tehamana (H.A. Pilsbry, 1928)
Triodopsis tennesseensis B. Walker & H.A. Pilsbry,1902
Ashmunella tetrodon H.A. Pilsbry & J.H. Ferriss,1915
Linisia texasiana (S. Moricand, 1833)
Polygyra tholus W.G. Binney, 1857
Ashmunella thompsoniana (C.M.F. Ancey, 1887)
Mesodon thyroidus (T. Say, 1816)
Mesodon thyroidus bucculentus (A.A. Gould, 1848)
Ashmunella todseni A. Metcalf & R. Smartt,1977
Ashmunella townsendi P. Bartsch, 1904
Allogona townsendiana (H.C. Lea, 1838)
Trilobopsis trachypepla (S.S. Berry, 1933)
Erectidens trichalis H.A. Pilsbry, 1953
Triodopsis tridentata (T. Say, 1816)