^. LSoniCiH Ins 



THE IB I^"" 



TENTH SERIES. 



Vol. VI. No. 4. OCTOBER 1918. 



XXVIII. — The Reversed Under Wing-Coverts of Birds and 

 their Modifications, as exemplified in the Birds of West 

 Africa. By George L. Bates, M.B.O.U. 



(Text-figures 5-12.) 



* Introduction. 



The two rows of feathers which form the subject of this 

 paper are those called the major and the median under 

 coverts of the wing, or the under coverts next to the reraiges. 

 The terms "major" and "median" were adopted doubt- 

 less on account of analogy with the upper coverts, but 

 are not as appropriate in the case of the under as of the 

 upper coverts, since, as will appear later, the major under 

 coverts are often the smaller of the two series, and the 

 median under coverts are often larger than either the major 

 or the minor coverts, or in many cases smaller than either. 

 The major and the median under coverts are distinguished 

 from all the other feathers on the underside of the wing, 

 in that they are placed facing downwards, or in the same 

 position as the remiges ; while all other feathers on the 

 underside of the wing face upwards, in the opposite position 

 to the remiges, i. e. stand face to face with them. Con- 

 sidered with reference to the remiges as a norm, it is these 



SEll. X.— VOL. VI. 2 Q 



