Volvarina socoae J. Espinosa & J.A. Ortea,1999
Volvarina sofiae J.A. Ortea & J. Espinosa,1998
Marginella solitaria (FOSSIL) R.J.L. Guppy, 1896 †
Dentimargo somalica T. Cossignani, 2001
Volvarina somalica F. Boyer, 2015
Volvarina somwangi F. Boyer, 2015
Hydroginella sordida (L.A. Reeve, 1865)
Eratoidea sotaventensis T. McCleery, 2011
Volvarina southwicki (C.A. Davis, 1904)
Volvarina sowerbyana (S.A.A. Petit De La Saussaye, 1851)
Hyalina sowerbyi W.H. Turton, 1932
Marginella sowerbyi (FOSSIL) W.M. Gabb, 1873 †
Marginella spadix S.G. Veldsman, 2016
Dentimargo spengleri M. Lussi, 2007
Marginella spengleri A. Aiken, 2014
Marginella spinacia S. Gofas & F. Fernandes,1988
Marginella spiralineata B. Hayes, 1994
Volvarina splendida T. Cossignani, 2005
Dentimargo spongiarum F. Boyer, 2001
Prunum springvalensis (FOSSIL) C.J. Maury, 1925 †
Serrata spryi (P.W. Clover, 1974)
Eratoidea statiola T. McCleery, 2011
Marginella stephaniae (FOSSIL) E.M. Da Costa, 1867 †
Marginella stephmani S.G. Veldsman & A. Aiken,2012
Dentimargo stewartiana (H.H. Suter, 1908)
Mesoginella stilla (C. Hedley, 1903)
Prunum storeria (J.P.Y. Couthouy, 1837)
Mesoginella strangei (G.F. Angas, 1877)
Cryptospira strigata (L.W. Dillwyn, 1817)
Cryptospira strigata unicolor J.J. Bert, 1985
Marginella strombiformis (FOSSIL) (J.E. Tenison-Woods,1877 †)
Marginella stuarti R.N. Kilburn, 1977
Serrata stylaster (F. Boyer, 2001)
Volvarina styria (W.H. Dall, 1889)
Dentimargo suavis (S.M. Souverbie, 1859)