450 BRITISH BIKDS. 



bars, and nearly all from the underparts, leaving the colour greyish white ; 

 the conspicuous pale tips to the secondaries and some of the primaries 

 have generally entirely disappeared ; the lower wing-bar and the pale edges 

 to the innermost secondaries have become very narrow ; and traces only 

 of the upper wing-bar are left. The autumn plumage is similar to that 

 of spring, but more brilliant, the eye-stripes and the wing-bars yellower, 

 and the upper parts a yellower green ; the mesial line on the crown remains 

 as obscure, and the uiiderparts scarcely yellower. In winter the same 

 amount of abrasion takes place as in summer ; but the upper parts do not 

 become so grey, and the eye-stripe and wing-bars retain a trace of yellow. 

 The Yellow-browed Warbler has several near allies. Two of these, which 

 breed in the Himalayas, P. erochroa and P. maculipennis , may be at once 

 distinguished by having the inner web of the two outside tail-feathers on 

 each side pure white. A third, P. proregulus, breeding in the Himalayas 

 and in the subalpine districts of South-eastern Siberia, differs from its 

 northern representative in having a bright yellow rump. Two other species, 

 P. subviridis and P. humii, also breeding in the Himalayas, but ranging 

 westwards, the one into Gilgit, north of Cashmere, and the other into 

 Turkestan, are more difficult to discriminate. They may generally be told 

 by their wing-formula, the second primary being usually intermediate in 

 length between the eighth and the ninth, whilst in the Yellow-browed 

 Warbler it is usually between the sixth and seventh. Fresh-moulted 

 examples of P. humii may be discriminated by their buff eye-stripe, of 

 P. subviridis by the much yellower green of its upper and the greener tint 

 of its underparts, and of both by their obscure upper wing-bar. 



