633 
Eryihrococca and Micrococca. 
recognizable on physiographical grounds is necessarily carried. These 
natural regions, ten in number, but in three instances conveniently sub¬ 
divisible, are here treated as primary ; to facilitate the use of a map, existing 
political areas are also indicated. To avoid confusion, the limits of these 
natural regions may be briefly stated:— 
I. North Africa. Mediterranean sea-board to the northern edge of 
the Sahara: Atlantic sea-board, between Tangier and Cape Nun, to the 
eastern fringe of the Libyan Waste. 
II. The Sahara. 
III. North Central Africa. Southern edge of the Sahara to the 
northern boundary of Upper Guinea and the Congo-Chad divide; Atlantic 
sea-board, between Lake Taniahya and the Gambia, eastward to Dar Fertit 
and the Nile-Chad divide. This region includes the catchment areas of 
the Senegal to its mouth, of the Niger and the Benue to their confluence, 
and of the streams that empty into Lake Chad. 
IV. West Africa. Belt roughly 200 miles wide inland from the 
Atlantic sea-board, the River Gambia on the north and Benguella on 
the south. This region includes the Lower Niger basin from Lokoja to 
the sea and the Lower Congo Basin below Stanley Pool; it admits of con¬ 
venient subdivision into:— 
(a) Upper Guinea. River Gambia to the River Sanaga; with Fer¬ 
nando Po. 
(b) Lower Guinea. River Sanaga to Benguella; with Prince’s Island 
and San Thome. 
V. West Central Africa. Catchment area of the Congo as far as 
Stanley Pool. 
VI. South-West Africa. Congo-Kunene and Congo-Zambesi 
divides southward to the Roggeveld, Nieuweveld, and Zuurberg ranges : 
Atlantic sea-board, between Benguella and Olifant’s River, eastward to Lake 
Nyasa, and the Kirk, Melsetter, Lebombo, and Drakensberg ranges. This 
region includes the catchment areas of the Cunene and the Orange-Vaal 
to their mouths, of the Zambesi to Tete, and of the Limpopo and other 
streams to the Mozambique frontier. 
VII. South-East Africa. Coast and Central zones of Cape Colony 
and Natal, between the Roggeveld, Nieuweveld, Zuurberg, and Drakensberg 
ranges and the sea, from Olifant’s River to Delagoa Bay. This region 
admits of convenient subdivision into :— 
(a) Cape. Olifant’s River to the Kei. 
(b) Natal. Kei River to Delagoa Bay. 
VIII. East Africa. Belt of varying width from the Indian Ocean 
