The Mergansers. 387 



length of the head, and extremely narrow. 

 The crown is furnished with a conspicuous 

 crest in both sexes. In the Goosander, 

 the crest of the male is thick and bushy, 

 and about one and a half inch in length \ 

 that of the female is longer, some of the 

 feathers measuring two and a half inches 

 in length, and more pointed. In the 

 Red-breasted Merganser, the crest of the 

 male is very narrow and straight, and in 

 a measure double, the longest feathers 

 measuring about three inches. The female 

 has a much shorter crest, also narrow and 

 straight, the feathers seldom exceeding a 

 length of an inch and a half. 



Mr. W. P. Pycraft has kindly drawn 

 my attention to the very peculiar formation 

 of the trachea in the Mergansers, by 

 means of which the sexes may be deter- 

 mined without dissection or regard to 

 plumage. The trachea of the male 

 Goosander has two enlargements ; that of 

 the female only one. In the male Red- 

 breasted Merganser, the trachea has one 

 enlargement ; that of the female has none 

 at all. These enlargements, or the absence 

 of them, can be easily felt by passing the 

 forefinger and thumb down the sides of 

 the neck of the birds, from the head to 

 the base of the neck. 



