In June 1918, I arranged to carry out a preliminary investigation of the habits and distribution of the tsetse-flies in the northern portion of the Mossurise district for a maximum period of three months on the understanding that the Mozambique Company would defray the general expenses of the expedition.

These notes include observations made on the mosquito fauna of Palestine, for the period July 1919 to August 1920.

The genus Dociostaurus, Fieb., which is synonymous with Stauronotus, Fisch., includes several species of locusts and grasshoppers injurious to agriculture in South-Eastern Europe, Central and Western Asia and North Africa, the well known Moroccan locust (Dociostaurus maroccanus, Thunb.) being one of the worst pests in Algeria, Tunisia, Asia Minor, the Caucasus and Turkestan. The systematics of the species of this genus are in a very unsatisfactory state, and this, together with the tendency of the species to individual variability, is the cause of many mistakes in their identification on the part of economic entomologists. The object of this paper is, therefore, to establish a more or less natural system of the species enabling everyone to identify them with certainty.