338 URIA GEYLLE. 



mottled with blackish-grey, the tip of each feather being of 

 the latter tint. The upper part of the head is dusky, the 

 back dull black, some of the scapulars ■white, tipped with 

 blackish-grey. The wings are greyish-black, with a white 

 patch, of A^hich the feathers are tipped Avith blackish-grey ; 

 the tail-feathers black. 



Progress toward Maturity. — The young moult in 

 October, and when the winter plumage is complete, it differs 

 little from that of the adult. In spring the young assume 

 the summer dress of their parents, and can hardly be distin- 

 guished from them. Individuals obtained at different periods 

 of the year present gieat diversity of markings, according to 

 the state of change. 



