Provides a thorough revision of Orthochtha together with seven allied genera, of which three are erected here. In all 36 species and 11 subspecies are treated of which 16 species and 5 subspecies are described here as new. All taxa are diagnosed, illustrated, keyed, mapped and their affinities discussed. The biogeography of the group is considered and a synopsis of the available information of the biology, ecology and economic importance given for each species.