The necessity for graphic representation of the distribution of insects and the diseases which are transmitted by them is now so evident as to need no special demonstration. But it is further obviously important that some uniform method should be adopted in the preparation of such maps, in order to make them intercomparable, and the object of the present notes is to suggest a comprehensive system of notation for the whole genus Glossina—a system which may be readily adapted for use in other genera or families of blood-sucking insects.