316 JAS. J. SIMPSON—ENTOMOLOGICAL 
a start at Yelwa, so that in my next report (on Southern Nigeria) the description 
of the Niger from Idah to the sea will form a consecutive account with this. 
The River Niger rises in the Kong Mountains near the borders of Sierra 
Leone, about 200 mile from the coast. It first runs in a north-easterly direction to 
Timbuktu (in 16° 40’ North and 2° 40’ West), a distance of nearly 500 miles. 
It then turns eastwards for about 150 miles to Buram Island, and afterwards 
south-easterly to Yelwa, a distance of over 450 miles. It is on this last stretch 
that it enters Northern Nigeria, near the small village of Tunga, which is about 
100 miles from Yelwa. From Tunga to the sea is roughly 700 miles, while from 
the source to Tunga is almost 1200 miles. From Yelwa it runs almost due south 
to Jebba, then eastwards to Baro, and from this point nearly due south to 
Southern Nigeria, which it enters at Idah, 289 miles from the coast. South of 
Abo, in Southern Nigeria, it spreads into an enormous delta with an intricate 
network of channels and creeks, and its various mouths extend over 200 miles of 
the coast. Its total length is therefore about 1900 miles, of which 1200 miles 
are outside British territory, 420 are in Northern, and 280 in Southern Nigeria. 
Tunga to Yelwa. 
This part of the river I was unable to examine, and as no blood-sucking flies 
have been recorded from this stretch, I shall content myself with quoting a short 
description* for the sake of completeness. ‘“ At Yelwa, the banks become low 
and swampy, the hills begin to recede from the river, and five miles further on, 
near the village of Sakassi, the last set of minor rapids (‘e., from south to 
north) occurs in the channel. Beyond Sakassi, the whole aspect of the river 
changes, the channel becomes broad and sandy, and is obstructed by nothing 
more serious than sand-bars. On the north bank a broad, swampy plain, with 
low rising ground in the distance, bounds the river as far as the mouth of the 
Kebbi. From Kebbi to the swamps of Illo, an open sandy plain stretches 
northwards between the river and the base of the plateau. On the south bank, 
the gently undulating plain which bounds the river stretches westward to the 
Dahomey border, broken only by some scattered groups of low-topped hills.” 
Yelwa to Jebba, 
This journey can be accomplished only in native canoes, and even by this 
means only during the season of highest water in the river, that is after the 
middle of the rains, owing to the numerous rocks which occur, and the number 
of rapids to be traversed. Six days were spent by the writer on this 
part of the river, and two at Bussa, the whole trip lasting from the 14th to 
the 21st of September. This method of examining a river is undoubtedly 
the best, as the rate of locomotion is slow, and it is possible to keep close in to 
the banks and land at any point which seems to merit special attention. The 
valley of the Niger from Yelwa to Ineku is wide and bounded by low hills with 
scanty forest growth ; at Ineku the river divides into two and encloses a large 
and extensive island, which stretches to Warra, where the two channels again join 
into one broad slow-flowing stream, with a wide flood-plain covered with long 
* From “The Geography and Geology of N. Nigeria,” by J. D. Falconer. 
