MERGANSER. 207 



The young birds of the first winter are generally brown ; the 

 head with a crest, of a rufous colour, but neither white, nor edged 

 with black, as in the adult male. 



The one figured in the PI. enlum. supposed to be the female, is 

 only a bird more advanced in plumage, probably in the second year; 

 it has the head and neck dark ash-colour, mottled with dusky black; 

 the crest short, and rust-coloured ; chin and throat whitish ; back, 

 wings, and tail, dusky, with a white line across the wings; breast 

 and belly white. The male of this bird, as in all others of the 

 Genus with which we are acquainted, is furnished with a bony 

 enlargement at the bottom of the trachea before the two branches 

 divaricate to pass into the lungs, but in shape it is not exactly like 

 any yet described ; it is oval, at its greatest length one inch and a 

 quarter, wholly bony, without any opening, and stands obliquely. 

 The trachea itself is about seven inches long from the entrance to 

 the divarication ; it passes downwards, of nearly the same diameter 

 for three-fifths of its length, when it increases for more than two 

 inches, the greatest diameter full five-eighths of an inch ; it contracts 

 again to three-fourths of an inch before it enlarges into the bony cist, 

 but not to the same size as the tube above. It may be observed too, 

 that the enlargement in the trachea does not change into the texture 

 of bone, as in the Red-breasted ; but remains cartilaginous through- 

 out the whole of its length. * 



This elegant species inhabits North America; appears at Hudson's 

 Bay the end of May, and builds close to the lake. The nest 

 composed of grass, lined with feathers from the breast; the female 

 lays from four to six white eggs ; the young at first are yellow ; are 

 fit to fly in July, and in autumn all depart southward. They first 

 appear at New York, and other parts, as low as Virginia and Caro- 

 lina, in November; frequent fresh waters, remaining through the 

 winter, and return northward in March : called at Hudson's Bay, 



* I am indebted to Mr Abbot, of Savannah, in Georgia, for the above ; as also for an 

 exact drawing of the trachea. 



