1920.] l)icriiriflrc in (he British Mmefim. 441 



Gold Coast — a fact wliich induced me to l)elieve Avitliout 

 careful exauiinatioii of material that the two forms must 

 be synonymous. An examination of tiic birds, five D. a. 

 divancatas from the Gold Coast and thirty-Hvc D. a. atadus 

 from the type locality, did not strengthen that view. The 

 latter birds could be (listin<i;uished by their more velvety- 

 blue appearance arul by the very dark lining to the quills 

 (a character which do s not seem to vary in D. a. atadus 

 but which in D. a. divaricatus certainly does vary, new 

 quills being darker and wearing lighter). 



A closer examination of the Gold Coast specimens 

 revealed the fact that birds from the coastal district were 

 all D. a. atnctus, those from the interior (the Hinterland) 

 all I), a. divaricatus. Thus we do not have, as it fix'st 

 appeared, two subspecies inhabiting the same country. 



A doubt as to the advis.ibility of keeping Dicrurus 

 adsimilis divaricatus [Dicrurus afer auctorum) separate 

 from D. adsiuii/is adsimilis induced me to make a very 

 thorough examination of these two forms, and the splen'did 

 material in the British Museum has enabled me to decide 

 this point to my satisfaction, 



D. adsimilis divaricatus is admittedly only distinguished 

 from the typical form by its relatively smaller size, and 

 whereas the former bird has an enormous range, the latter 

 species is confined to South Africa. 



•' South Africa ^' is given as the type locality of D. a. 

 adsimilis, whereas the type locality of D. a. divaricatus is 

 Senegal ; this is fortunate, for Avhereas the average wing- 

 measurement of birds from Senegal is 139 mm., that of 

 Cape Culony birds is 135'4 mm. The Drongos in northern 

 Africa are obviously a smaller race than those in South 

 Africa, but, as so often happens, the birds from the meeting- 

 ground (Angola on the west coast and the Transvaal on 

 the east coast) approach one another very closely in size. 

 In fact, it is exceedingly difficult to say for certain to which 

 form the Angola birds in particular belong. 



Mr. Oberholser, in his review of the subspecies of D. ad- 

 similis (Proc. U.S. Nat. Mus. xxviii. 1905. pp. 918-920), 

 noticed the same fact in the specimens from Angola which 



