Radix jaksici (FOSSIL) (Š. Brusina, 1902 †)
Radix japonica J.C. Jay, 1857
Radix javanica (A. Mousson, 1894)
Radix jordii C.R. Altaba, 2007
Boskovicia josephi (FOSSIL) (Š. Brusina, 1874 †)
Lymnaea juribeica N.D. Kruglov& Y.I. Starobogatov, 1984
Lymnaea kafanovi N.D. Kruglov& Y.I. Starobogatov, 1984
Lymnaea kamtschatica (A.T. von Middendorff,1851)
Lymnaea kashmirensis B. Prashad, 1925
Stagnicola kayseris P. Glöer & M.Z. Yildirim,2006
Lymnaea kazakensis A. Mozley, 1934
Aenigmomphiscola kazakhstanica N.D. Kruglov& Y.I. Starobogatov, 1981
Galba kenesensis (FOSSIL) (Halaváts, 1903 †)
Stagnicola kennicotti F.C. Baker, 1933
Lymnaea kingi F.B. Meek, 1876
Valenciennius kiseljaki (FOSSIL) (Gorjanovic-Kramberger,1901 †)
Lymnaea klaici (FOSSIL) Š. Brusina, 1884 †
Lanx klamathensis H.B. Hannibal, 1912
Radix kobelti (FOSSIL) (Š. Brusina, 1884 †)
Undulotheca kochi (FOSSIL) Gorjanovic-Kramberger,1923 †
Radix korlevici (FOSSIL) (Š. Brusina, 1884 †)
Radix kovaci T.A. Neubauer& M. Harzhauser, 2015
Valenciennius krambergeri (FOSSIL) (R. Hoernes, 1901 †)
Stagnicola kreutzii (FOSSIL) (Lomnicki, 1886 †)
Valenciennius kujalnicus (FOSSIL) Taktakishvili, 1962 †
Lymnaea kunashirica N.D. Kruglov& Y.I. Starobogatov, 1989
Lymnaea kurejkae Gundrizer& Y.I. Starobogatov, 1979
Radix kurelaci (FOSSIL) (Š. Brusina, 1902 †)
Lymnaea kurenkovi N.D. Kruglov& Y.I. Starobogatov, 1989
Lymnaea kurilensis N.D. Kruglov& Y.I. Starobogatov, 1989
Boskovicia kuzmici (FOSSIL) Š. Brusina, 1897 †
Radix labiata (E.A. Rossmässler, 1835)
Radix laevigata (FOSSIL) (K.E.I. von Eichwald,1853 †)
Radix lagotis (L. von Schrenck, 1803)
Radix lagotis costulata (E.C. Von Martens, 1874)