Coelatura ratidota (Charmes, 1885) Tanzania
Elliptio raveneli T.A. Conrad, 1834 South Carolina
Alasmidonta raveneliana I. Lea, 1834 North Carolina, Swain County
Nephronaias ravistella (P.M.A. Morelet, 1849) Guatemala
Unio ravoisieri G.P. Deshayes, 1847 Morocco, cap Cantin40 mm
Ligumia recta (J.B.P.A. Lamarck, 1819) Pennsylvania130 mm
Lampsilis reeveiana (I. Lea, 1852) Missouri, Camden County
Obliquaria reflexa C.S. Rafinesque, 1820 Alabama48,5 mm
Amphinaias refulgens (I. Lea, 1868) USA, Louisiana54,7 mm
Unio regularis (FOSSIL) Fric, 1869 † Czech Republic, Kounic
Inversiunio reinianus (W. Kobelt, 1879) Japan32,7 mm
Pseudodon resupinatus E.C. Von Martens, 1902 Vietnam, Tonkin
Acuticosta retiaria (P.M. Heude, 1883) China, Anhui17,2 mm
Reticulatus reticulatum (FOSSIL) (Phillips) † UK, England
Reticulatus reticulatus (C.T. Simpson, 1900) Honduras
Obovaria retusa J.B.P.A. Lamarck, 1819 Kentucky, Kentucky River
Pleurobema riddellii I. Lea, 1861 USA, Texas
Lemiox rimosus C.S. Rafinesque, 1831 Alabama47 mm
Solenaia rivularis (P.M. Heude, 1877) China, Ning-kouo-fou
Elliptio roanokensis I. Lea, 1838 Georgia, Savannah
Alasmidonta robusta A.H. Clarke, 1981 Pennsylvania
Lamprotula rochechouarti (P.M. Heude, 1875) Poyang Lake, Jiangxi, China125 mm
Coelatura rothschildi (H. Neuville& J.G. Anthony, 1906) Kenya, Turkana Lake
Coelatura rotula H.A. Pilsbry& J.C. Bequaert, 1927 Congo, Pointe Noire
Fusconaia rotulata (B.H. Wright, 1899) Florida, Escambia County
Glebula rotundata (J.B.P.A. Lamarck, 1819) Alabama61,6 mm
Potamilus rovirosai (H.A. Pilsbry, 1900) Mexico, Tabasco
Nephronaias rowellii (I. Lea, 1859) Mexico, Tehuantepec
Pleurobema rubellum T.A. Conrad, 1834 Alabama
Martensnaias rubicunda (E.C. Von Martens, 1900) Guatemala
Pleurobema rubrum C.S. Rafinesque, 1820 Tennessee70 mm
Psorula rudis (C.T. Simpson, 1900) Guatemala
Cuneopsis rufescens (P.M. Heude) China, Fujian Province54,3 mm
Parreysia rugosa (J.F. Gmelin, 1791) India, Bombay
Pachynaias rugososulcata (I. Lea, 1866) Mexico, Tabasco