The blood-sucking flies here dealt with were collected in Hong Kong by Dr. H. Macfarlane, the Government Bacteriologist, and Mr. Adam Gibson, M.R.C.V.S., the Colonial Veterinary Surgeon, and were forwarded by them to the Imperial Bureau of Entomology. The collection comprises not many species, but long series of several species, such as Tabanus rubidus, Wied., T. albimedius, Wlk., T. sanguinarius, Wlk., and T. mandarinus, Schiner.