634 
Prain.—A Review of the Genera 
sea-board between Delagoa Bay and the River Juba, inland to the Lebombo, 
Melsetter, and Kirk ranges, Lake Nyasa, a line from the northern end of 
Nyasa to the eastern base of Kilimanjaro, thence to the eastern base of 
Kenia, thence to Lake Rudolf: limited on the north by a line joining the 
northern ends of Lakes Rudolf and Stefanie and projected eastward to the 
River Dawoe, thereafter by the Dawoe-Juba. This region admits of con¬ 
venient subdivision into :•— 
(a) Mozambique. Delagoa Bay to the Rovuma. 
(&) Zanzibaria. Rovuma River to the Juba; with Mafia, Zanzibar, 
and Pemba. 
IX. East Central Africa. Limited on south and west by a line 
from the northern end of Nyasa to Tanganyika, by Lake Tanganyika, the 
Congo-Nile and the Nile-Chad divides as far as Dar Fertit; on the east by 
the western boundary of East Africa as far as the northern end of Lake 
Rudolf, thereafter by a line from Lake Rudolf to the River Sobat; on the 
north by the Sobat and the Bahr-el-Arab. This region includes the catch¬ 
ment area of the Upper Nile as far as Sobat with the massifs of Ruwenzori, 
Kilimanjaro, Elgon, and Kenia. 
X. North-East Africa. Limited on the west by North Africa, the 
Sahara, and North Central Africa; on the south by East Central and East 
Africa. The region includes Egypt, Nubia, the Eastern Sudan, Abyssinia, 
and Somaliland, with Yemen and Socotra. 
In the first three regions, North Africa, the Sahara, and North Central 
Africa, no species of Erythrococca has yet been met with ; nor has any 
species been found in the western, or Cape, subdivision of South-East 
Africa. In all the other regions species of Erythrococca occur in numbers 
varying from nineteen in West Africa to one in North-East Africa. 
Of the nineteen species which occur in West Africa eleven are found in 
Upper Guinea and nine are endemic there; nine are met with in Lower 
Guinea and six of these are endemic. Only one of the nineteen is found 
both in Upper and in Lower Guinea; this species extends across West 
Central Africa as far as Uganda in East Central Africa. One species is 
common to Upper Guinea and West Central Africa ; two others are common 
to Lower Guinea and West Central Africa ; yet another extends from Upper 
Guinea only across West Central to East Central Africa. 
In West Central Africa there are nine species only; four of these are 
endemic. Of the remaining five, three extend to West Africa only ; the 
other two extend both to West Africa and to East Central Africa. 
In South-West Africa there are only two species, one of them being 
endemic and local; the other, which is very widely spread in the region, 
extends from German South-West Africa and Bechuanaland to Northern 
Rhodesia and German East Africa. 
