Keys and diagnoses illustrated with line drawings and colour photographs for the identification of larvae and adult males of the genera of Heptageniidae of the world and female adults of North American Heptageniidae genera are provided. Siberionurus McCafferty is recognized as a junior objective synonym of Ecdyogymnurus Kluge. Epeiron Demoulin is shown to be congeneric with Rhithrogena Eaton.