_Amyda_ Fitzinger, Ann. Wiener Mus. Naturg., 1:110, 120, 127, 1835; type, _Amyda subplana_ Fitzinger by subsequent designation (Fitzinger 1843:30). _Gymnopus_ Duméril and Bibron, Erpét. Gén., 2:472, 1835; new (substitute) name for _Aspidonectes_ Wagler. _Pelodiscus_ Fitzinger, Ann. Wiener Mus. Naturg., 1:110, 120, 127, 1835; type, _Pelodiscus sinensis_ Fitzinger by subsequent designation (Fitzinger, 1843:30). _Platypeltis_ Fitzinger, Ann. Wiener Mus. Naturg., 1:109, 120, 127, 1835; type, _Platypeltis ferox_ by subsequent designation (Fitzinger, 1843:30). _Potamochelys_ Fitzinger, Syst. Rept., p. 30, 1843; type, _Aspidonectes javanicus_ Wagler (= _Testudo cartilaginea_ Boddaert) by original designation. _Tyrse_ Gray, Cat. Tort. Croc. Amphis. Brit. Mus., p. 48, 1844; type, _Tyrse nilotica_ Gray (= _Testudo triunguis_ Forskål) by tautonomy (_Tyrse_, a name for the Nile River). _Callinia_ Gray, Proc. Zool. Soc. London, p. 222, 1869; new (substitute) name for _Aspidonectes_ of Agassiz (1857:403); type, _Callinia spicifera_ (mispelling for _spinifera_) Gray by subsequent designation (Stejneger, 1907:514). _Euamyda_ Stejneger, Bull. Mus. Comp. Zool., 94:7, 9, 12, 1944; new (substitute) name for _Amyda mutica_ of Agassiz (1857:399); type, _Amyda mutica_ Agassiz by monotypy. _Type Species._--_Trionyx aegyptiacus_ (= _Testudo triunguis_ Forskål). _Diagnosis._--Cutaneous femoral valves absent; width of postorbital arch of skull less than diameter of orbit; pterygoids usually not contacting opisthotics; carapace lacking prenuchal bone and marginal ossifications; nuchal bone lacking conspicuous ventral ridges; posterior margin of nuchal overlying first pair of pleurals; lateral parts of nuchal bone overlying second pair of ribs; neurals seven or eight, rarely six or nine; pleurals seven or eight pairs, posterior one or two pairs sometimes in contact medially; distinct suture usually present between hyoplastra and hypoplastra; most laterad prong of posteromedial process of hypoplastra inserted between bifid anterolateral process of xiphiplastra.