Collections recently received by the Imperial Bureau of Entomology, chiefly from Natal, have brought to light several interesting new forms in this group of flies, and their study has yielded certain unlooked for results which it appears desirable to place on record, together with descriptions of the new species, the types of which have been presented by the Bureau to the British Museum. The opportunity has been taken of publishing revised keys to the African species of Banksinetta and Taeniorhynchus.