Birds from British East Africa and Uganda. 425 



Coguno, Port. East Africa, which has been named C super- 

 ciliosm, cf. Sclater, Ibis, 1911, p. 735, but which, as shown 

 by two blue feathers ou the nape, I take to be the immature 

 of C. burchellii. 



Although the immature C. burchellii can and has been 

 confounded with C. supercHiosus, a series shows that charac- 

 ters are present by which the species can be separated. In 

 the immature of C. burchellii the eye-stripe is nearly always 

 present, but only in exceptional instances is it as broad as 

 in C. superciliosus ; where streaks are present on the nape 

 and mantle, they do not usually extend so far down the 

 back as in C. superciliosus, also the uuderparts are not 

 streaked and banded ; in specimens where the underparts 

 are more or less streaked and banded, thus approaching 

 C superciliosus in this respect, it will usually be found that 

 the streaks on the nape and mantle are altogether lacking 

 or only few in number. 



On comparing young birds in first dress of C. burchellii 

 from southern Africa with young birds in first dress of 

 C. superciliosus from Nyasaland and Uganda, no distin- 

 guishing characters can be noted, both having the head and 

 nape mottled and streaked, more or less uniform with the 

 back, though certainly some young C. burchellii have blackish 

 on the head and nape, and the difficulty would appear to 

 arise as to how birds in this dress can be separated in 

 localities where they occur together ; but young birds of 

 C. burchellii from the northernmost limits of its range have 

 the top of the head, the ear-coverts, and the nape black, 

 with a more or less distinct eye-streak and some streaks ou 

 the nape, thus being clearly separable from the young of 

 C. superciliosus from the southernmost limits of its range. 



The races and ranges of the two species appear to be as 

 follows : — 



Centropus superciliosus superciliosus. 

 Centropus superciliosus Hempr. & Ehr. op. cit. 

 Mantle and inner secondaries earthy brown, top of head 

 and ear-coverts a little darker than the mantle. 



