Nuculopsis shumardensis (FOSSIL) (J.W. Hall, 1856 †)
Ennucula siberutensis (K.H.J. Thiele& S.G.A. Jaeckel, 1931)
Ennucula similis (P.M. Rhind & J.A. Allen,1992)
Nucula similis J. de C. Sowerby, 1813
Nucula similis gallica (FOSSIL) M. Glibert & Poel, 1965 †
Pronucula similis (FOSSIL) A.E.M. Cossmann& G. Pissarro, 1904 †
Nucula simplex (FOSSIL) G.P. Deshayes, 1842 †
Nucula sinaria (FOSSIL) W.H. Dall, 1898 †
Leionucula sinegorskiensis (FOSSIL) Kalishevich, 1969 †
Nucula sinnatella (FOSSIL) A.E.M. Cossmann †
Lamellinucula sinuatella (FOSSIL) (Cossmann 1908) †
Nucula smithvillensis (FOSSIL) H.B. Stenzel & J. Twining,1957 †
Nucula smitki (FOSSIL) Author unknown †
Truncacila snatolensis (FOSSIL) V.N. Sinelnikova, 1991 †
Lamellinucula soriensis (FOSSIL) F.E. Eames, 1951 †
Nucula sphenopsis (FOSSIL) T.A. Conrad, 1865 †
Nucula stantoni (FOSSIL) L.W. Stephenson, 1923 †
Nucula stephana (FOSSIL) Henry, 1876 †
Acila stillwaterensis C.S. Weaver & K.V.W. Palmer,1922
Nucula storrsi (FOSSIL) Stanton, 1895 †
Ennucula strangei (A. Adams, 1856)
Ennucula strangeiformis (R.K. Dell, 1956)
Nucula striatissima G. Seguenza, 1877
Palaeonucula strigilata (FOSSIL) (G.A. Goldfuss, 1837 †)
Nucula striolata A. Adams, 1856
Nucula studeri (FOSSIL) d'Archaic, 1850 †
Nucula suahelica (K.H.J. Thiele& S.G.A. Jaeckel, 1931)
Leionucula subaraucana (FOSSIL) D. Frassinetti, 1997 †
Nucula subcuneata (FOSSIL) d'Orbigny, 1849 †
Nucula subluxa R.N. Kilburn, 1999
Nucula submargaritacea (FOSSIL) M. Rouault, 1849 †
Acila submirabilis J. Makiyama, 1926
Palaeonucula subobliqua (FOSSIL) (A.V.M.D. D'Orbigny,1849 †)
Leionucula suboblonga (FOSSIL) (R.O. Wilckens, 1907 †)
Nucula subovalis (FOSSIL) G.A. Goldfuss, 1837 †