Toxolasma paulus (I. Lea, 1840)
Chamberlainia paviei (P.M.A. Morelet, 1891)
Parreysia pecten (H.B. Preston, 1912)
Actinonaias pectorosa (T.A. Conrad, 1834)
Utterbackiana peggyae R.I. Johnson, 1965
Medionidus penicillatus (I. Lea, 1857)
Trapezoideus peninsularis C.T. Simpson, 1900
Utterbackiana peninsularis A. Bogan & W.R. Hoeh,1995
Epioblasma penita (T.A. Conrad, 1834)
Psorula percompressa (E.C. Von Martens, 1887)
Parreysia perconvexa H.B. Preston, 1912
Unio peregrinus B. Phillips, 1829
Hamiota perovalis (T.A. Conrad, 1834)
Pleurobema perovatum T.A. Conrad, 1834
Villosa perpurpurea (I. Lea, 1861)
Epioblasma personata (T. Say, 1829)
Amphinaias petrina (A.A. Gould, 1855)
Ptychorhynchus pfisteri (P.M. Heude, 1874)
Scabies phaselus (I. Lea, 1856)
Lamellidens phenchooganjensis H.B. Preston, 1912
Unio pictorum (C. Linnaeus, 1758)
Unio pictorum rostratus J.B.P.A. Lamarck, 1819
Barynaias pigerrima (J.C.H. Crosse& P.H. Fischer, 1893)
Radiatula pilata (I. Lea, 1866)
Hyriopsis pinchoniana (P.M. Heude, 1883)
Cuneopsis pisciculus (P.M. Heude, 1874)
Delphinonaias planivalvis (P.M.A. Morelet, 1851)
Unio planus (FOSSIL) D. Mongin, 1963 †
Venustaconcha pleasii (W.A. Marsh, 1891)
Pleurobema plenum I. Lea, 1840
Barynaias plexus (T.A. Conrad, 1838)
Amblema plicata (T. Say, 1817)
Amblema plicata perplicata (T.A. Conrad, 1834)
Cristaria plicata (W.E. Leach, 1815)
Cristaria plicata spatiosa S. Clessin, 1875