Agalmyla Blume (including Dichrotrichum de Vriese and Tetradema Schltr.) (Gesneriaceae-Cyrtandroideae) is revised. Ninety-seven species are recognized, 62 of them newly described, and these are divided into three sections with distinct geographical ranges. Sect. Agalmyla (24 species) is restricted to the Malay Peninsula, Sumatra, Java, Borneo and Palawan; sect. Exannularia (19 species) is the only section on Sulawesi and has a few species nearby; sect. Dichrotrichum (54 species) is represented in the Philippine Islands (excluding Palawan) by 13 species, in the Moluccas by two species, and in New Guinea by 39 species. No species is found in more than one of these areas and the key to sect. Dichrotrichum is therefore split between the Philippine species and those on the Moluccas and New Guinea. There are thus four keys altogether. The affinity and geographical distribution, both of the whole genus and of the sections, are discussed, and special attention is given to distribution of species in relation to the geological terranes of New Guinea. Points of interest and taxonomic importance in the morphological features are noted in a separate section.