MEHGANSERINjE. 
193 
the Mergansers, although few in number, seem yet to 
form a very distinct family, of which the following are 
among the most important characters : — The body is 
large, elongated, elliptical, and depressed ; the neck long 
and slender ; the head oblong, compressed, anteriorly 
narrowed. Bill rather long, straight, or a little rearcuate, 
slender, tapering, and toward the end becoming nearly 
cylindrical ; the edges of both mandibles furnished with 
lamellse much narrower than in the Ducks, and in the 
larger species conical, acuminate, and directed backward ; 
the unguis oblong, of the same breadth as the mandibles, 
and the upper abruptly decurved. Mouth rather narrow, 
but dilatable ; tongue fleshy, with lateral bristles, and lace- 
rated tip ; oesophagus very wide ; stomach rather small, 
roundish, very muscular, with thick, rugous epithelium ; 
intestine long, rather wide, with moderately large cooca, 
and globular cloaca. Trachea variously enlarged, and 
always having an enormous dilatation at its lower extre- 
mity, partly bony and partly membranous ; bronchi wide* 
Eyes rather small. Nostrils oblong, submedial. Ear- 
aperture very small. Legs short, placed far behind ; tarsi 
very short, much compressed ; toes four ; the first very 
small, elevated, arcuate, with a lobiform membrane ; an- 
terior toes long, with full membranes, the inner with a 
bilobate web ; claws small, little arched, compressed. 
Plumage moderately full, firm, glossy; the feathers curv- 
ed, with a small down-plumule ; head and nape crested ; 
wings short, of moderate breadth, convex, pointed, the 
first quill longest ; tail short, much rounded, of from 
fourteen to eighteen, stiffish, tapering feathers. 
The males, which are larger than the females, assume 
in summer somewhat of their appearance. As in the 
Anatinse, there is a speculum on the wing. Their food 
consists chiefly of fish, for which they dive ; their flight 
is quick, and direct ; but they w r alk with difficulty. They 
pass the summer in the colder regions, form a bulky nest, 
