Since the publication of my paper dealing with the taxonomic characters of the genital armature of the males of all the then known species of tsetse-flies* Mr. E. E. Austen has very kindly allowed me to examine a paratype of his Glossina medicorum; and Mr. Guy A. K. Marshall, on behalf of the Entomological Research Committee (Tropical Africa), has submitted to me the specimen of G. tabaniformis, Westwood, upon which Mr. Austen based his re-description† of the male of this species. I am extremely indebted to these gentlemen for giving me the opportunity of making a microscopical examination of these insects, as thereby it has enabled me to complete my observations on the male armature of the tsetse-flies, and also to complete the set of drawings illustrative of the main morphological characters of these organs.