174 GREAT ATIK. 



two latter and the sides of the head are white in autuTmn 

 and winter. Breast, white; back, glossy black. 



Greater and lesser wing coverts, black; primaries, black, 

 the longest quill feather is only four inches in length; 

 secondaries, black, their tips white, forming a boundary to 

 the wing; tertiaries, black; greater and lesser under wing 

 coverts, white. Tail, black; upper tail coverts, black; under 

 tail coverts, white. The legs, short, and placed far back, 

 are, as the toes and claws, blackish; webs, blackish brown. 



Selby says that this species undergoes a double moult, 

 and Dr. Fleming noticed that the change took place in a 

 few days. 



In the young bird it would appear that the bill becomes 

 only gradually grooved, and the neck is mottled with black 

 and white. 



