BLUE-HEADED WACxTAIL. 563 



and sides of the face beneath the ear-coverts, white ; the 

 throat, breast, belly and lower tail-coverts, bright gamboge- 

 yellow : legs, toes and claws, black. 



The old male in autumn loses much of the yellow tinge 

 on the back, and the body beneath is of a primrose-yellow. 



The length of the male is six inches and a half. From 

 the carpal joint to the end of the wing, three inches and one- 

 eighth : the second primary rather longer than the third or 

 fourth, and, when the wing is folded, just surpassing the 

 longest tertial. 



The whole length of an adult female is six inches and 

 one-eighth. In the breeding-season the head, ear-coverts and 

 nape are slate-grey; over the eye and ear-coverts a white 

 streak ; the back dull olive ; the edges of the wing-coverts 

 and tertials nearly white ; the chin and throat white ; the 

 breast, belly and lower tail-coverts pale king's-yellow. 



In autumn the head of the female is mixed with greenish- 

 brown, the white superciliary streak remaining ; the chin 

 white ; throat and breast buffy-white ; belly and lower tail- 

 coverts primrose-yellow. 



The young male in his first autumn resembles the adult 

 female in the breeding-season, except that the grey of the 

 head is more mixed with brown, and the yellow of the upper 

 part of the breast is clouded with brown and buffy-orange. 

 In the following spring the grey feathers of the head still 

 exhibit a slight mixture of olive-green, and the chin is yel- 

 low, which in the more adult male is white. 



The young female in spring has the head and ear-coverts 

 gi-eyish-brown ; the chin and throat buffy-white ; the upper 

 part of the breast mottled with brown ; the lower part of the 

 breast and the body beneath, primrose-yellow, enriched with 

 a mixture of king's-yellow. 



This bird may be distinguished from our common Yellow 

 Wagtail, next to be described, by the white streak over the 

 eyes and ear-coverts, which, though variable in length, 

 appears to be permanent at all seasons, and by the bluish- 

 grey head, which is more or less conspicuous, also, at all 

 seasons, but particularly in summer. 



