Pitar securiformis (FOSSIL) T.A. Conrad, 1865 †
Securella securis (FOSSIL) (Shumard, 1858 †)
Mysia segregata (FOSSIL) A.E.M. Cossmann, 1887 †
Meretrix semiarata (FOSSIL) A.E.M. Cossmann, 1906 †
Dosinia semilaevis (FOSSIL) R.A. Philippi, 1887 †
Dosinia semiobliterata G.P. Deshayes, 1853
Chionopsis semiplicata (FOSSIL) (Nomland, 1917 †)
Pitar semipunctata (FOSSIL) (T.A. Conrad, 1848 †)
Paphia semirugata (R.A. Philippi, 1847)
Callista semisulcata (G.B. Sowerby, 1851)
Meroena semisulcata (FOSSIL) (J.B.P.A. Lamarck,1806 †)
Costacallista semperi (J.B.P.A. Lamarck, 1818)
Meroena separata (FOSSIL) (G.P. Deshayes, 1857 †)
Dosinia sericea (L.A. Reeve, 1850)
Tapes sericeus A. Matsukuma, 1986
Petricolaria serrata (G.P. Deshayes, 1853)
Aphrodora sewelli (J. Knudsen, 1967)
Leukoma seymourensis (FOSSIL) W.H. Dall & Oschner,1928 †
Meretrix shantii (FOSSIL) Abbass, 1972 †
Timoclea siamensis (H. Lynge, 1909)
Dosinia sicarisinus (FOSSIL) B.F. Kensley & Pether,1986 †
Pitar silicifluvia (FOSSIL) W.H. Dall, 1916 †
Tivelina siliqua (FOSSIL) A.A. Olsson, 1928 †
Pitar simiensis (FOSSIL) (R.N. Nelson, 1925 †)
Tawera similicentrifuga (J.M.R.M. Viader, 1951)
Hyphantosoma simonnei (FOSSIL) A. Dey, 1961 †
Pitar simpsoni (W.H. Dall, 1895)
Callocardia sincera (FOSSIL) W.H. Dall, 1903 †
Pitar sinedepressus (FOSSIL) (R.N. Nelson, 1925 †)
Cyclina sinensis (J.F. Gmelin, 1791)
Marama singularis (FOSSIL) (J. Marwick, 1927 †)
Venus sinuosa (J.B.P.A. Lamarck, 1818)
Timoclea smithiana M. Huber, 2010
Katherinella smithvillensis (FOSSIL) H.B. Stenzel & al.,1957 †
Tivela snatolana (FOSSIL) Slodkewitsch, 1938 †