i920.] On the African Dicruridse. 439 



XIII. — A Review* of the African DicruricUe in the British 

 Museum f. By David A. Bannerman, M.B.E., B.A., 

 M.B.O.U., F.R.G.S. 



Whilst naming the Drongos iu the Clnisty collection from 

 the Belgian Congo in the summer of 1919 I took the oppor- 

 tunity to work through the whole group of" African Dicrurida?. 



Very little work seems to have been done on this group 

 since Shelley's last volume (v., 1912) of the ' Birds of 

 Africa,' edited by Mr. W. L. Sclater, and Keichenow's 

 ' Vogel Af rikas ' were published. 



Oberholser worked through the adsiniilis group in the 

 Proc. U.S. Nat. Mus. xxviii. 1905, pp. 918-920, and his 

 conclusions seem to be t|uite sound. As I disagree in some 

 important points with the conclusions arrived at by Shelley 

 and Keichenow, 1 here publish the results of my own 

 investigations. 



In all, I recognise 8 species and subspecies from the main- 

 land of Africa, Fernando Po, and Zanzibar as follows : — 



1. Dicninis mudedng tnodentug. Prince's Island. 



2. Dicrurus niodestus comciuua. African mainland. 



3. Dicrurus adsimilis adsimilits. African mainland. 



4. Dicruribis adsimilis divaricatus. African mainland and Zanzibar. 



5. Dicrurus adsimilis atactus, African mainland. 



6. Dicrurus atripennis. African mainland. 



7. Dicrurus sharpei. African mainland. 



8. Dicrurus ludivirji, African mainland. 



I have found it impossible to make anything like a really 

 serviceable Key to this group, as where we have to depend 

 for distinguishing characters largely on the amount and 

 shade of the " gloss "" ou the plumage, and on the relative 

 degvec of " fork " in the tail, a concise Key to the species 

 and subspecies is generally not very satisfactory. Instead 

 I have mentioned the most striking characters, given the 



* The Keview here published was writleu in July 1919. U\vin<j' to 

 lack of space iu ' The Ibis ' it has been held over by the Editor. If, in 

 consequence, the conclusions arrived at are '' out of date," the author 

 hopes that the unavoidable delay in publi.'^hing- will be taken into con- 

 sideration. Owiug to absence abroad he has been unable to revise the 

 paper here submitted. 



t Published by pernussion of tiie Trustees of the Uritish Museum. 



