Mytilus scaphoides (FOSSIL) H.G. Bronn, 1831 †
Triasoperna schafhaeutli (FOSSIL) (Stur, 1851 †)
Crenomytilus schencki (FOSSIL) (G.D. Hanna& L.G. Hertlein, 1938 †)
Adula schmidtii (L. von Schrenck, 1867)
Arvella sculptilis (A. Adams, 1862)
Brachidontes sculptus (T. Iredale, 1939)
Bathymodiolus securiformis T.A. Okutani, K. Fujikura& T. Sasaki, 2004
Limnoperna securis (J.B.P.A. Lamarck, 1819)
Perna semielliptica (FOSSIL) Seeley †
Gregariella semigranata (L.A. Reeve, 1858)
Musculus semigranosa (FOSSIL) R. Tate, 1886 †
Modiolus semilaevigatus (FOSSIL) G.P. Deshayes, 1858 †
Brachidontes semilaevis (K.T. Menke, 1848)
Vilasina seminuda (W.H. Dall, 1897)
Musculus seminudus (FOSSIL) G.P. Deshayes, 1830 †
Mytilus seminummuarius (FOSSIL) H. Guo, 1985 †
Promytilus semiorbicularis (FOSSIL) Y. Fang, 1987 †
Musculus semiradiatus (J.C. Verco, 1908)
Arcuatula senhousia (W.H. Benson, 1842)
Bathymodiolus septemdierum J. Hashimoto & T.A. Okutani,1994
Arcoperna serica (FOSSIL) (H.G. Bronn, 1831 †)
Crenella serica (FOSSIL) T.A. Conrad, 1860 †
Septifer serratus (FOSSIL) (Melleville, 1843 †)
Brachidontes setiger (R.W. Dunker, 1857)
Solamen shitakaraensis (FOSSIL) Honda 1989 †
Mytilus shulapsensis (FOSSIL) McLearn, 1942 †
Mytilus shunbetsuensis (FOSSIL) Suzuki & S. Uozumi,1983 †
Limnoperna siamensis (P.M.A. Morelet, 1866)
Modiolus silentiensis (FOSSIL) McLearn, 1926 †
Mytilus similis (FOSSIL) Münster, 1841 †
Botula similoides (FOSSIL) Vokes 1946 †
Lithophaga simplex (T. Iredale, 1939)
Idas simpsoni (J.T. Marshall, 1900)
Dacrydium simulator (FOSSIL) C.R. Laws, 1936 †
Musculus singularis (FOSSIL) R. Tate, 1886 †