This study presents a taxonomic revision of the orchid genera Ania, Hancockia, Mischobulbum and Tainia. Keys to the genera and species are given, together with a desciption of each species. All species are also represented by line drawings. In toto, 31 species and 2 subspecies are recognised. Four new species are described and 1 new combination is made. Many names are reduced to synonymy. A short discussion is given of the taxonomic history of each genus.