— 78 — 



But I have observed in C. s. superciliosus, C. s. senegalensis, 

 Anomalospiza imherhis Q and other birds, in which brown enters 

 into the colour of the plumage, that this brown colour at the 

 period of moulting or' during moult — owing to the wear and 

 long use of the dress — is considerably darker than in the fresh 

 dress, exactly as in the case of the green plumage of a number 

 of species of Melittophagus, which changes into a more or less 

 cobalt-blue. 



This individual is in the beginning of the moult, and that 

 is why the colour of the back is different from that of specimens 

 in fresh plumage. 



Wing 205 mm. Tarsus 49 mm. 



Irides blood-red, bill and legs black. 



1 venture to point out here that if this subject of colour- 

 changing of the dress was paid more attention to by a number 

 of systematisers, and birds of certain families from one district 

 only were compared with others from other districts in the 

 same stage of plumage, many birds now described as doubtful 

 would probably not have been advanced as new species or sub- 

 species. 



Centropus senegalensis incertus Granvik. 

 1 (5 6. 4. Mount Elgon. 



Immediatly below the eastern slopes of Elgon, in the acacia- 

 country, I saw two specimens of this Cuckoo and as I wandered 

 about in the tall grass I was fortunate enough to find the pair's nest. 



I hid in the vicinity and then noticed that one of the birds 

 flew into the nest and sat on the eggs. After a while I flushed 

 this bird and shot it. It then turned out to be the male. 

 Total length in flesh wing tarsus bill tail 



370 mm. 165 mm. 42 mm. 30 mm. 200 mm. 



Colour of irides, red; bill black; legs dark-grey; Grant 

 (Ibis 1915, p. 423) says "middle claw white", but in this specimen 

 all the claws are black. 



At the Berlin Museum I examined 35 spec, of Centropus 

 senegalensis senegalensis from different parts of Africa, shot at 

 different periods of the year. All of them have a green wash 

 on the head and a still deeper one on the rectrices. In this 

 respect the Elgon form differs from all of them, because it is 

 entirely devoid of this wash both on the head and tail, but is dull 

 and soot-coloured instead. Hence it cannot be classed among 

 this sub-species, even if the respective measurements agree. 



It reminds one somewhat of C. senegalensis ischadensis of 

 Reichenow (Journ. f. Orn. 1915, p. 124) but the latter has 



occidentalis in the coloration, and as it seems to me, that the latter 

 is a good form (Grant, op. cit., makes it synonymous with monachus) 

 my bird might by termed as above. 



