﻿278 S. A. NEAVE — NOTES ON THE BLOOD-SUCKING 



probably more to be discovered. The most abundant of these species is 

 C. grahami, Aust., which I found in vast numbers in the forests of the Semliki 

 Valley, in November 1911. It was there a most terrible pest, and made life 

 almost unbearable. The hours when it was worst were between 8 and 10 a.m., 

 and from about 4 p.m. until sunset. It did not bite after dark. 



One species, which appears to be new to science, was taken near the sea-shore 

 at Lamu, British East Africa, and presumably breeds in salt or brackish water. 

 It is said to be a great pest at certain seasons. 



Genus JOHANNSENIELLA, Will. 



This genus is only known from Africa, up to the present, by two females 

 of the recently described Johannseniella fulvitlwrax, Aust., which I took in May 

 1911, on the Yala River, in North Kavirondo, British East Africa. They were 

 taken at night, shortly after sunset. 



Genus Ceratopogon, Mg. 



A few insects of this genus were taken on the southern slopes of Mount Elgon, 

 in June 1911. The Research Committee have also received it from Nyasaland 

 from Sir David Bruce, on whose authority it is stated to attack man. 

 Dr. Spurrier, of Zanzibar, also states that insects of this genus are a serious pest 

 there. 



Family Culicidae. 



It is not possible for lack of time to give a detailed account of the mosquitos 

 collected, though the records of all the species obtained are included in the 

 general list. Apart from this, the collection made was by no means a representa- 

 tive one, it being very difficult to collect these insects at all exclusively when 

 constantly on the move. Among the more interesting species taken was Skusea 

 pembae?isis, Theo., of which a few specimens were obtained in March 1912 near 

 Lamu, British East Africa. It attacks man readily, but was only really trouble- 

 some for an hour about sunset and again at sunrise. It seems to occur only on 

 the sea-shore, often great distances from fresh water, and presumably breeds in 

 the sea. The most interesting mosquitos from an economic standpoint are of 

 course the Anophelinae, the carriers of malaria. They are widely distributed 

 in all the countries under consideration, but certainly seem scarcer in individuals, 

 if not in species, in the damper parts of Western Uganda than, for instance, in 

 the drier and more open country to the north or in the Nyanza Province on the 

 eastern side of the Lake. In this latter region several species, particularly 

 Anopheles (Myzomyia) costalis, are extraordinarily abundant, and malaria is 

 consequently very prevalent. 



Family Simuliidae. 



Genus Simulium, Latr. 



The species of this genus, of which several were taken over a large area, have 

 not yet been systematically studied. They seem to be chiefly numerous in well- 

 wooded, damp localities, often at considerable elevations, as on the slopes of 

 Mt. Kenya. 



