6 (No. 99 GEOGRAPHY basin of the central Congo. It is bordered on the south east by the Katanga, a continuation of the high veldt of South Africa and Rhodesia , and on the south by the lower lands of the Angola plateau. In the east it rises to the mountains bordering the great rift in which lie Lakes Albert, Edward, Kivu, and Tanganyika, and on the north-east to a lower plateau which forms the divide between the waters of the Congo and the Nile ; while on the west the low Congo plateau merges into the Crystal Mountains. To the west of these mountains lies the small coastal region.

Coastal Region . - Behind the Atlantic coast of the Belgian Congo, which is generally low and sandy, there are cliffs which form the escarpment of a low plateau . Upon this plateau are considerable areas of marsh-land, in which the rivers pursue winding and uncertain courses. Farther inland the land rises through a second sandy plateau to the region of Mayumbe, which occupies the remainder of the country north of the Congo basin and west of the Crystal Mountains. It is a hilly district, and the numerous rivers which traverse it are frequently interrupted by falls and rapids. In the valleys, and on the lower slopes of the hills, there is a more or less dense tropical forest, but else where brushwood and savanna are the prevailing types of vegetation . The banks of the Congo are frequently covered with mangrove forests , while farther inland there is again savanna. The region as a whole contains considerable areas of fertile soil, and numerous planta tions have been established within it.

Crystal Mountains. — These mountains run along the western coast of Africa from Cameroon to Angola. Within the Belgian Congo they form a great barrier between the coastal region and the central basin of the Congo. Their average height seldom exceeds 2,500 ft. , the most conspicuous parts of the range being the massif