Littoridina patagonica (A.V.M.D. D'Orbigny,1835)
Littoridina pebasana (FOSSIL) T.A. Conrad, 1874 †
Dyris pebasensis (FOSSIL) Wesselingh, 2006 †
Littoridina pedrina K. Miller, 1879
Heleobia peiranoi (W.K. Weyrauch, 1963)
Tryonia perclathrata K. Sakurai, 1983
Tryonia peregrina R. Hershler, H.P. Liu& J.J. Landye, 2011
Cochliopa perforata F.G. Thompson & R. Hershler,1991
Aroapyrgus petenensis (P.M.A. Morelet, 1851)
Lyrodes peteningensis (A.A. Gould, 1852)
Heleobia picium (A.V.M.D. D'Orbigny)
Cochliopina picta (H.A. Pilsbry, 1910)
Tryonia pilsbryi (J.P.E. Morrison, 1945)
Littoridina piscium (A.V.M.D. D'Orbigny,1835)
Pyrgophorus platyrachis F.G. Thompson, 1968
Tryonia porrecta (J.W. Mighels, 1845)
Littoridina profunda (H. Hass, 1955)
Tryonia protea (A.A. Gould, 1855)
Tryonia pseudocircumstriata Czaja & Estrada-Rodriguez,2015
Littoridina pueloensis W.A. Biese, 1944
Tryonia pulchella (A. Adams, 1860)
Littoridina pusilla F. Haas, 1949
Pyrgophorus putialis (H.B. Baker, 1930)
Aphaostracon pycnus F.G. Thompson, 1968
Mexithauma quadripaludium D.W. Taylor, 1966
Tryonia quitobaquitae R. Hershler, 1988
Dyris regularis (FOSSIL) Wesselingh, 2006 †
Dyris renemai (FOSSIL) Wesselingh, 2006 †
Feliconcha reticulata (FOSSIL) Wesselingh, 2006 †
Aphaostracon rhadinus F.G. Thompson, 1968
Aroapyrgus rhegoides (P.M.A. Morelet, 1851)
Cochliopina riograndensis (H.A. Pilsbry& J.H. Ferriss, 1906)
Heleobia rionegrina (J.M. Gaillard, 1974)
Tryonia robusta R. Hershler, 1989
Heleobia robusta F. Da Silva& I.L. Veitenheimer-Mendes, 2004