332 APPENDIX. 
remarkably homogeneous character. Of this Ethiopian 
region the portion which extends on the western side of 
the continent, between the rivers Gambia and Congo, 
and consequently embracing Guinea and the Gold Coast, 
and reaching as far as 25° East long., is of a distinct 
character, being occupied by dense forests. To this sub- 
region the name of "West African" has been applied. An- 
other sub-region, the " South African," is formed of that 
part of the continent south of the tropic of Capricorn, but 
extending northwards along the east coast as far as 
Mozambique. 
The remainder of Africa, from the tropic of Cancer 
to the river Gambia on the west coast, and including 
Senegambia, Timbuctoo, South Egypt, Abyssinia, the east- 
ern half of Africa (including the great lakes, and Zanzi- 
bar), and reaching from Mozambique on the east to Angola, 
Benguela, and Damara Land on the west coast, is con- 
sidered as forming a third sub-region, to which the inappro- 
priate name of "East Africa" has been applied. It is in 
the south-eastern portion of this third sub-region that the 
collection of insects formed by Mr. F. Oates was obtained. 
The surface of all this sub-region is described by Mr. 
A. R. Wallace as " generally open, covered with a vegeta- 
tion of high grasses or thorny shrubs, with scattered 
trees and isolated patches of forest in favourable situa- 
tions. The only parts where continuous forests occur are 
on the eastern and western slopes of the great Abyssinian 
plateau, and on the Mozambique coast from Zanzibar to 
Sofala. The whole of this great district has one general 
zoological character. Many species range from Senegal 
to Abyssinia ; others from Abyssinia to the Zambesi ; and 
a few, as Mimgos fasciatiLS and Phacochcsrus cBtJiiopiciis (to 
which great numbers of species of insects may be added), 
range over the entire sub-region." Various species of 
quadrupeds and birds are mentioned, which are found in 
Gambia, Abyssinia, and South-east Africa, but not in 
the West African sub-region ; and yet Mr. Wallace adds, 
" Although this sub-region is so extensive and so gener- 
ally uniform in physical features, it is by far the least 
