Almost all of the studies here reported were made in one small region, so that very little new information was secured on the ranges of the species of mosquitos under consideration.

Our investigations regarding breeding-places were limited to a few species. Aëdes vittatus was found occasionally breeding in tree-holes in Ibadan. Aëdes irritans adults were taken at Ibadan, which is so far inland that this species must sometimes breed in places other than crab-holes at the edges of salt or brackish water. We did not, however, find the larvae of this species at Ibadan. The favourite breeding-place of Eretmopodites chrysogaster was found to be small collections of water in fallen leaves (especially those of cocoa trees) lying in moist and densely shaded places. Because of the abundance of Mansonia africana in places practically free from Pistia, we conclude that in the vicinity of Lagos it must breed abundantly on other plants. The long flight range of this species was taken into consideration in arriving at this conclusion. An extensive search failed, however, to reveal these plants. M. uniformis, also abundant in the vicinity of Lagos, does not breed there upon Pistia, but an extensive search failed to reveal its breeding-place.