Monoplex keenae (A.G. Beu, 1970)
Ameranella kewi (FOSSIL) (R.E. Dickerson, 1915 †)
Monoplex klenei (G.B. III Sowerby, 1889)
Turritriton kobelti (H. von Maltzan, 1884)
Monoplex krebsii O.A.L. Mörch, 1877
Monoplex kritscheri (FOSSIL) M. Harzhauser, 2014 †
Turritriton labiosus (Wood, 1828)
Gyrineum lacunatum (J.W. Mighels, 1845)
Charonia laevigata (FOSSIL) (P.M.T. de Serres,1829 †)
Charonia lampas (C. Linnaeus, 1758)
Charonia lampas capax H.J. Finlay, 1926
Charonia lampas macilenta J.T. Kuroda & T. Habe,1961
Charonia lampas nodifera (J.B.P.A. Lamarck, 1822)
Charonia lampas pustulata (F.M. Euthyme, 1889)
Charonia lampas rubicunda (G. Perry, 1811)
Charonia lampas rubicunda powelli B.C. Cotton, 1956
Charonia lampas sauliae (L.A. Reeve, 1844)
Charonia lampas weisbordi J. Gibson-Smith, 1976
Septa landaui (FOSSIL) A.G. Beu, 2010 †
Fusitriton laudandus H.J. Finlay, 1927
Sassia lejeunii (FOSSIL) (Melleville, 1843 †)
Gyrineum lessonae (FOSSIL) L.M.D. Bellardi, 1873 †
Gyrineum lessonae occidentalis (FOSSIL) A.E.M. Cossmann& M.A. Peyrot, 1923 †
Sassia leucostomoides (Sowerby, 1846)
Sassia lewisi M.G. Harasewych& E.J. Petuch, 1980
Monoplex lignarius W.J. Broderip, 1833
Reticutriton lineatus (W.J. Broderip, 1833)
Gyrineum longicaudatum A.G. Beu, 1998
Monoplex longispira (FOSSIL) A.G. Beu, 2010 †
Cymatium lotorium (C. Linnaeus, 1758)
Halgyrineum louisae (Lewis, 1974)
Monoplex macrodon A. Valenciennes, 1832
Fusitriton magellanicus (J.H. Chemnitz, 1788)
Ranella magnifica (FOSSIL) Martin, 1879 †
Cabestana manawatuna (FOSSIL) C.A. Fleming, 1943 †