454 
GEOLOGICAL STKUCTUKE. 
Chap, XXIII, 
E.) on the 7tli May. This is a stream of thirty yards wide, and, 
Mice the Quilo, Loange, Chilcapa, and Loajima, contains both alli¬ 
gators and liippopotami. We crossed it by means of canoes. 
Here, as on the slopes down to the Quilo and Chikapa, we had an 
opportunity of viewing the geological structure of the country,-— 
a capping of ferruginous conglomerate, which in many parts looks 
as if it had been melted, for the rounded nodules resemble masses 
of slag, and they have a smooth scale on the surface; but in aU 
probabiMty it is an aqueous deposit, for it contains water-worn 
pebbles of all sorts, and generally small. Below tins mass, lies a 
pale-red hardened sandstone, and beneath that, a trap-Mke wliin- 
stone. Lowest of all lies a coarse-grained sandstone containing a 
few pebbles, and in connection with it, a white calcareous rock is 
occasionally met with, and so are banks of loose round quartz 
pebbles. The slopes are longer from the level country above, the 
further we go eastward, and everywhere we meet with circumscribed 
bogs on them, surrounded by clumps of straight, lofty, evergTeen 
trees, which look extremely gTaceful on a ground of yellowish 
grass. Several of these bogs pour forth a solution of iron, which 
exhibits on its surface the prismatic colours. The level plateaus 
between the rivers, both east and west of the Moamba, across 
which we travelled, were less woody than the river glens. The 
trees on them are scraggy and wide apart. There are also large 
open grass-covered spaces, with scarcely even a bush. On these 
rather dreary intervals between the rivers, it was impossible not 
to be painfully struck with the absence of all animal life. Hot a 
bird was to be seen, except occasionally a tomtit, some of the 
Sylviadw and JDrymoica, also a black bird (Dicrurus Ludwigii, 
Smith), common throughout the country. We were gladdened 
by the voice of bnds only near the rivers, and there they are 
neither numerous nor varied. The Senegal longclaw, however, 
maintains its place, and is the largest bMd seen. We saw a 
butcher-bird in a trap as we passed. There are remarkably few 
small animals, they having been hunted almost to extermination, 
and few insects except ants, which abound in considerable number 
and variety. There are scarcely any common flies to be seen, 
nor are we ever troubled by mosquitoes. 
The air is still, hot, and oppressive; the intensely bright sun- 
liglrt glances peacefully on the evergreen forest leaves, and all 
