128 BIEDS OF EGYPT. 



Upper plumage slaty grey, shading off on the rump and 

 upper tail-coverts into liriglit greenish yellow ; wings dark 

 brown, the secondaries broadly edged with yellowish white ; 

 tail dark brown, the three outer feathers on each side white ; 

 underparts white, usually strongly tinted with sulphur- 

 yellow from the chest downwards, and always brightest on 

 the under tail-coverts ; a distinct white eyebrow ; beak pale 

 brown, darkest towards the tip ; legs flesh-brown ; irides 

 brown. 



In summer plumage both sexes assume a black throat. 



The tail is longer than in any of the Yellow Wagtails! 



Entire length 7-5 inches; culmen 0-45; wing, carpus to 

 tip, 3'3 ; tarsus 0"8. 



Fig. Gould, B. of Eur. pi. 147. 



90. Bddytes flava (Linn.). Grey-headed Yellow Wagtail. 



This and the next two species are generally considered to 

 be mere varieties of the same bird ; and in large series of 

 specimens it is difficult, if not impossible, to draw the line 

 between them. However this may be with birds from other 

 localities, in Egypt and Nubia they appear to keep perfectly 

 separate. I only met with the true B. Jlava of Linnaeus 

 about the middle of April in Nubia, travelling northward in 

 large flocks, out of which I killed more than twenty speci- 

 mens without finding the least variation in plumage ; while I 

 had already found B. cinereocapilla, one of the most abundant 

 bii'ds in Egypt, in March. The true B. flava may be most 

 readily distinguished by a well-defined white eyebrow, which 

 is absent in the next two species or subspecies. I would 



