716 SYSTEMATIC SYNOPSIS. — LAMELLIROSTEES— AN SERES. 
with black on the back j crown of head black ; a large white area on the wing formed by many 
of the coverts and bases of the secondaries ; axillars also white. A 9 or young $ specimen 
has the back blackish, spotted with yellowish-brown ; the general ferruginous color dappled 
with dusky ; and two blackish stripes on each side of head. Length about 13.00 ; wing 5.00 j 
tail 3.00 ; tarsus 1.00 ; culmen 1.40. A small and curious duck of C. and S. Am. and W. I., 
accidental in the U. S., as on Lake Champlain and in Wisconsin (see Proc. Bost. Soc. Nat. 
Hist., vi, 375 ; xiv, 151 ; Amer. Nat., v, 441 ; and Baird, B. N. A., 1858, 925). 
69. Subfamily MERGING: Mergansers. 
Bill narrow, more or less nearly cylindrical, the nail hooked and overhanging, the 
lamelliB highly developed into prominent serrations, the nasal fossae lengthened and narrowed. 
Excepting the character of the bill, the ' saw-bill ' or ' fishing-ducks ' are simply Fuligtdincs, 
somewhat modified in adaptation to a more exclusively animal regimen ; the lamellae of the 
bill become detainers of large objects, not sifters or strainers of minute things. The principal 
point in their economy is ability to pursue fish under water, like Cormorants, Loons, and 
other birds of lower orders. The nature of their food renders their flesh rank and unpalatable ; 
in buying a ' duck,' notice the bill, that it be not cylindric, hooked, and saw-toothed ; the 
flap of the hind toe is as in any Sea Duck ; the tarsi are much compressed. The gizzard 
is rather less muscular than in most ducks ; the intestines and their cceca are shorter ; the 
syringeal capsule of the ^ is very large, irregular, partly membranous ; the trachea has 
other dilatations (fig. 3). Birds of this group inhabit fresh as well as salt water, and are 
abundant in individuals if not in species. There are about 8 species, chiefly of the Northern 
Hemisphere, but several occur in South America : we have 3, commonly and perhaps properly 
referred to 2 genera, Mergus and Lojjhodgtes. 
300. MER'GUS. (Lat. mergus, a diver ; mergo, I merge in.) Mergansers. Fishing Ducks. 
Saw-bills. Bill as above said. Nostrils median or sub-basal. Tarsi compressed, anteri- 
orly scutellate, with smaller plates on sides and behind, one-half to two-thirds as long as middle 
toe and claw. Hind toe lobate. Tail rounded, usually one-half or more the length of the 
pointed Avings. Head usually crested. 
Analysis of Subgenera and Species. 
Bill not shorter than head, mostly red. Serrations of bill acute, recurved, claw-like. Tarsus about two- 
thirds as long as middle toe. Tail about half as long as wings. Crest low, flimsy, occipital, if any. 
Head green or brown. (Mergus.) 
Nostrils near middle of bill. Frontal feathers beyond those on side of bill. Crest scarcely developed, 
(f with breast uncolored merganser 743 
Nostrils near base of bill. Frontal feathers not beyond those on side of bill. Crest better developed. 
(f with breast and sides colored serrator 744 
Bill shorter than head, mostly black. Serrations of bill low, oblique, not hooked. Tarsus about half as 
long as middle toe. Tail more than half as long as wing. Crest of cf highly developed, erect, com- 
pressed, semicircular, coronal as well as occipital. (Lophodytes.) 
Nostrils near base of bill. Frontal feathers produced beyond those on sides of bill . . . cucuUatus 745 
743. M. mergan'ser. (Lat. mergtis and anser, diver-goose. Fig. 199.) Merganser. Goos- 
ander. Nostrils near middle of bill. Frontal feathers extending acutely on culmen about 
half way from those on side of bill to nostrils ; loral feathers sweeping in nearly vertical line 
across side of base of upper mandible, about opposite those on side of lower mandible. Head 
scarcely crested, merely a line of little lengthened feathers along occiput and nape, better 
developed, however, in 9 than in $. Adult $ : Bill and feet vermilion-red in breeding 
season, with black hook ; iris carmine. Head and neck splendid dark green. Under parts 
salmon-colored, the flanks and lower belly marbled or watered with dusky. Upper parts 
gh)ssy-black, fading to ashy on rump and tail ; surface of wing mostly pure white, crossed by 
a black bar formed by bases of greater coverts. Primaries and outer secondaries black, inter- 
