BIRDS OF THE BRITISH ISLES. 369 



1RO60'0 6ull. 



Ross's Gull {Rhodostethia rosea, Macgillivray) is an ex- 

 ceptionally rare straggling winter migrant to the British 

 Isles, and inhabits the Polar Regions. The adult in 

 summer plumage has the head and neck nearly white, the 

 latter encircled with a narrow black collar ; remainder of 

 upper plumage, pearl-grey, changing into white on the tips 

 of greater wing-coverts and secondaries ; outer web of first 

 quill feather, black ; tail, white and cuneated ; under parts, 

 white, tinged with rose colour on breast and abdomen ; 

 irides, hazel; bill, black; legs and feet, bright red. Length, 

 about thirteen inches. The adults in winter lack the black 

 collar, 



24 



