RESEARCH IN BRITISH WEST AFRICA. Bhi 
bush. At this part of the river G. tachinoides are fairly abundant, but no G. 
palpalis were seen; this is due, no doubt, to the nature of the vegetation. The 
town of Derri is situated at the confluence of the Garara and the Niger. In the 
dry season it stands high and dry, and is surrounded by marshes and pools left 
by the falling river, but in the wet season it is an island on which water rises 
to the floors of the houses. In every respect it resembles Mureji at the con- 
Huence of the Kaduna and the Niger (Pl. IX, fig. 2). The following mosquitos 
were obtained during my stay at this town :— Culex invidiosus, Myzomyia funesta, 
Mansonioides uniformis, Banksinella lutealateralis and Ludlowia mimomyiaformis. 
It might be well to summarise briefly a few of the outstanding results of 
this trip :— 
(1.) The journey was made at the height of the dry season—from Decem- 
ber 17th to December 25th. 
(2.) The banks of the River Garara, wherever scen, were covered with dense 
vegetation, and numerous kurimis occur everywhere in the vicinity of the river. 
In such situations G. palpalis was almost invariably found. 
(3.) The only other species of tsetse seen were G. tachinoides and G. longipalpis. 
The former was found at Dagu, near Wada, Evua, and between Gerinya and 
Derri. In all these places the bush was open and removed some distance from 
the river. G. longipalpis was caught at Evua, and between Wada and Edzu, in 
both cases in open country and still further removed from water. 
(4.) No TABANIDAE were seen during the trip. 
(5.) Mosquitos : Mansonioides uniformis was caught at both Mama and Derri; 
while at the latter town Culex invidiosus, Myzomyia funesta, Banksinella luteola- 
teralis and Ludlowia mimomyiaformis were also obtained. 
(6.) Ticks were seen only at Mama. 
(7.) The whole region along the Garara has a bad reputation for horses, 
so that none are kept in the vicinity of the river, every attempt having met with 
failure. 
(8.) At towns more remote, such as Lapai and those situated on high ground, 
egy., Gau, horses and cattle are kept with impunity. 
(j) Derri to Bagana. 
Having thus completed the examination of the Garara River, I decided to 
visit the Province of Bassa, as sleeping sickness had been reported from this 
region, and little or nothing had been done from an entomological standpoint. 
For this purpose, it was necessary to go to Bagana on the south bank of the 
Benue River. The journey was made in three stages : (1) to Kotonkerifi on the 
Niger, by canoe ; (2) Kotonkerifi to Umaisha, by road; and (3) Umaisha to 
Bagana, by canoe. 
The trip from Derri to Kotonkerifi occupies only about five hours, and is 
accomplished in native dug-out canoes. The river bank is mostly overgrown by 
dense shade-trees, but there are numerous sand-banks, which are partially covered 
with long xerophilous grass. Only one tsetse was seen, apparently G. tachinoides. 
Numerous crocodiles were observed basking on the sand-banks. The native 
town of Kotonkerifi is about three miles distant from the point of disembarking, 
