766. 
736 SYSTEMATIC SYNOPSIS. —LONGIPENNES — GAVIA. 
border curves gently upward to give passage to the nostrils. The union of the two lateral 
halves leaves a well-marked acutely-angular recess over the culmen. There is a well-marked 
lateral longitudinal groove. Curve of uail regular, gradual. Commissure straight to the 
nostrils, then gradually declinato-convex. Eminentia symphysis slightly marked; commissure 
long, gonys short, a little concave, gape wide. Outline of feathers on the bill much as in the 
Larine, but supero-laterally they do not run so far forward, nor with so acute an angle. Nos- 
trils placed far forward, lateral, linear, direct, pervious, their opening a little club-shaped. 
Bill horn, deepening into black; feet black. Pilewm and occipital crest brownish-black ; this 
color extending iwnuch below the eyes, and occupying the feathers on the ramus of the inferior 
maxilla. Acuminate feathers of the neck light yellow. Back, wings, tail, upper wing-coverts, 
under tail-coverts as far as the flanks, deep blackish-brown. Under parts, from chin to abdo- 
men, and neck all round (except the acuminate feathers), pure white. Length about 20.00; 
extent 48.00; wing 14.00; biil 1.75; tarsus 2.00. Nearly adult: Generally as in the 
preceding, but with a row of brown spots across the breast; the sides under the wings 
transversely barred with white and brown; the purity of the dark color of the abdomen 
interrupted by some touches of white. The legs wholly black, and the tail-feathers project- 
ing as much as in the fully adult. Intermediate stage: The band of dark spots across the 
breast is widened and enlarged, so that the whole breast appears brown, mottled with white ; 
the sides under the wings are conspicuously barred with white and brown; the white ef the 
under parts is continued down over the abdomen to the under tail-coverts; the pure brown 
of these parts which obtains in the adult now only appearing as transverse bars among the 
white. Upper tail-coverts and some of the wing-coverts barred with white. Bases of pri- 
maries inferiorly white. Central tail-feathers only project an inch. ‘Tarsi irregularly blotched 
with chrome-yellow —the hind toe and nail being of this color. Young-of-the-year: Bill 
much smaller and weaker than in the adult, light-colored to beyond the nostrils, when it 
becomes brownish-black. Feet and toes mostly bright yellow, the terminal portions of the 
latter black. The whole body everywhere transversely waved with dull rufous. On the head, 
neck, and under parts, this rufous forms the predomimating color; and the bands are ex- 
ceedingly numerous, of about the same width as the intervening dark color. On the flanks 
and under tail-coverts the bars become wider, and almost white in color. On the back and 
wing-coverts the brownish-black is the predominating color; and if any rufous is present, it 
is merely as narrow edging of the feathers. Quills and tail-feathers brownish-black, darker 
at tips; whitish toward bases of primaries on inner webs. Light rufous predominating on 
head and neck; a dusky spot before eye. Ail the above stages traceable from one to another. 
Dusky state: The bird is very nearly wnicolor ; blackish-brown all over; this color deepeuing 
into quite black on the pileum; lightening iuto fuliginous-brown on the abdomen, with a 
slight gilding of the black on the sides of the neck. The whitish bases of the primaries 
exist. The feet are in the chromo-variegated condition. The central tail-feathers scarcely 
project half an inch. N. N. Am., ranging to the Middle States in winter ; not common. 
S. parasi’ticus. (Lat. parasiticus, parasitic.) PARAsiTic JAGER. Adult, breeding plum- 
age: Bill much shorter than head or tarsus; as high as broad at the base. Culmen broad, 
flattened, scarcely appreciably convex to the unguis, which is moderately convex. Rami very 
long; gonys very short; both somewhat concave in outline. Eminentia symphysis small but 
well-marked. Tomia of superior mandible at first ascending and a little concave; then 
descending and a little convex ; very concave toward the tip. Cere without oblique strie ; 
with a straight longitudinal suleus on each side of the eculmen. Feathers extending far on 
superior mandible, with a curved free outline, so broad that the feathers of the sides meet over 
the culmen. Feathers on lower mandible also projecting considerably, almost filling the tri- 
angular suleus on the side as well as the angular space between the rami. Wings moderately 
long, strong, pointed ; first primary much the longest; rest regularly and rapidly graduated ; 
