716 SYSTEMATIC SYNOPSIS.— LAMELLIBOSTBES — ANSEBES. 



with black on the back ; 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 ? 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 ; 

 tail 3.00 ; tarsus 1.00 ; culmen 1.40. A small and curious duck of G. 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, 154 ; 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 

 lamellse 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 Fuligulince, 

 somewhat modified in adaptation to a more exclusively animal regimen ; the lameUse 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 coeca 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 

 refeiTed to 3 genera, Mergus and LophodyteS. 

 300. MEK'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 wings. Head usually crested. 



Analysis of Subgenera cmd Species. 



BUI not shorter than head, mostly red. Serrations of bill acute, recurved, claw-like. Tarsus about two- 

 thirds as long as middle too. Tail about half as long as wings. Crest low, flimsy, occipital, if any. 

 Head green or brown. (Mebgus.) 

 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. 



cf 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 J 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 . . . cucuUatua 745 



743. M. mergan'ser. (Lat. mergms and amer, diver-goose. Fig. 499.) 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 vermUion-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 

 glossy-black, fading to ashy on rump and tail ; smface of wing mostly pure white, crossed by 

 e black bar formed by bases of greater coverts. Primaries and outer secondaries black, inter- 



