Friersonia iridella (H.A. Pilsbry& L.S. Frierson, 1907) Mexico, San Luis Potosì
Solenaia iridinea (P.M. Heude, 1874) China, Jiangsu166 mm
Villosa iris (I. Lea, 1829) Alabama44,4 mm
Pronodularia japanensis (I. Lea, 1859) Japan, Akita43 mm
Elliptio jayensis I. Lea, 1838 Florida58 mm
Elliptio jayensis buckleyi I. Lea, 1843 Florida31,5 mm
Lamellidens jenkinsianus (W.H. Benson, 1862) Myanmar
Acuticosta jianghanensis J. He & Z. Zhuang, 2013 China, Hubei Province133 mm
Anodonta johnseni (FOSSIL) H.D. Russell, 1935 † Canada, Alberta, Division No. 2
Inversiunio jokohamensis (H.F.A. von Ihering,1893) Japan, Hokkaido
Ptychobranchus jonesi (H. Van Der Schalie,1934) Florida, Walton County
Oxynaia jourdyi (L.J. Morlet, 1886) Cyprus50 mm
Oxynaia jourdyi corrugata (P. Dautzenberg& H. Fischer, 1905) Vvietnam, Van Yen35 mm
Oxynaia jourdyi ponderosa (P. Dautzenberg& H. Fischer, 1905) Vietnam, Hanoï60 mm
Unio jowikolensis (FOSSIL) Cox, 1955 † Niger40 mm
Elliptio judithae A.H. Clarke, 1986 Michigan, Wayne County
Unio katzeri (FOSSIL) Š. Brusina, 1904 † Bosnia
Amphinaias keineriana (I. Lea, 1852) Alabama, Coosa River
Anodonta kennerlyi I. Lea, 1860 Canada, British Columbia
Radiatula khadakvaslaensis H.C. Ray, 1966 India, Cuddalore
Solenaia khwaenoiensis S. Panha & Deein, 2004 Thailand113 mm
Coelatura kipopoensis G. Mandahl-Barth, 1968 Congo, Pointe Noire34,8 mm
Unio kirchbergensis (FOSSIL) Krauss, 1852 †
Lamprotula kouangensis (C.T. Simpson, 1900) Anhui, China
Coelatura kunenensis (A. Mousson, 1887) South Africa
Psoronaias kuxensis L.S. Frierson, 1917 Guatemala
Unio lacaziana (FOSSIL) D. Dupuy, 1843 † France, Aquitaine
Pyganodon lacustris (I. Lea, 1852) New York, Herkimer County
Lamellidens lamellatus (I. Lea, 1838) Myanmar, Bhamo
Schistodesmus lampreyanus (W. Baird & A. Adams,1867) Poyang Lake, Jiangxi, China54 mm
Fusconaia lananensis L.S. Frierson, 1901 USA, Texas
Elliptio lanceolata I. Lea, 1827 North Carolina, Raleigh45 mm
Arconaia lanceolata (I. Lea, 1856) Dongting lake, Hunan, China136 mm
Lepidodesma languilati (P.M. Heude, 1874) Poyang Lake, Jiangxi, China174 mm
Rostrunio lapparenti (FOSSIL) (D. Mongin, 1963 †) Niger94 mm