1921 .] collected in Southern Cameroon. 93 
exactly the same changes of plumage are apparent in the 
ten birds from Nyasaland. 
In dealing with examples of the Black Cuckoo from north¬ 
east and north-west Africa the problem is considerably 
complicated by the occurrence in Uganda, British East 
Africa, southern Abyssinia, and northern Angola of the bird 
known as Cuculus jacksoni Sharpe, immature examples of 
Cuculus clamosus having been confused by many workers 
with the young of C. jacksoni. Unfortunately both forms 
occur side by side in many districts—even in the same 
forests; and the very variable plumage exhibited bjr im¬ 
mature birds of C. clamosus has made the status of the two 
forms and the range which they occupy a difficult task to 
unravel. 
From northern central Africa we have examples of the true 
Black Cuckoo from Uganda, British East Africa, southern 
Abyssinia, eastern Belgian Congo, the Galla country, Niam- 
Niam country, northern Angola, Gold Coast, and Sierra 
Leone. The adult black birds are indistinguishable from 
those from South Africa, and the immature specimens exhibit 
the same remarkable variety in the colour of the plumage— 
from the indistinctly barred birds with an indication of 
rufous appearing amongst the feathers of the breast to a 
curious grey bird in the collection of Sir Frederick Jackson. 
Cuculus jacksoni. 
[Cuculus jacksoni Sharpe, Bull. B. O. C. xiii. 1902, p. 7 — 
Type locality : Toro, Uganda.] 
At first glance typical examples of C. jacksoni look like a 
very distinct Cuckoo, but the type is not quite adult. The 
upper parts are glossy blue-black as in C. clamosus , but the 
underparts are very dissimilar to any phase of plumage 
exhibited by South African specimens in the National 
Collection, and resemble much more nearly C. g. gabonensis. 
The breast is dark chestnut, the throat greyish, and the 
rest of the underside, from the chest to and including 
the under tail-coverts, is strikingly banded with black 
