736 SYSTEM A TIC SYNOPSIS. — L ONGIFENNES — GA VI^. 
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 cuhnen. There is a well-marked 
lateral longitudinal groove. Curve of nail 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 
Larince, but supero-laterally they do not run so far forward, nor with so acute an augle. Nos- 
trils placed far forward, lateral, linear, direct, pervious, their opening a little club-shaped. 
Bill horn, deepening into black ; feet black. Pileum and occipital crest brownish-black ; this 
color extending much 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; bill 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 appe^irs brown, mottled with white ; 
the sides under the wings are conspicuously barred with white and brown ; the white of the 
under parts is continued down over the abdomen to the under tail-coverts ; the pure brown 
of these parts wliich 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 infei'iorly 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 predominating 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 predominatiug (»n 
head and neck ; a dusky spot before eye. Ail the above stages traceable from one to another. 
Dusky state : The bird is very nearly unicolor ; blackish-brown all over ; this color deepening 
into quite black ow the pileum ; lightening into fiiliginous-brcnvn 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 chrorao-variegated condition. The central tail-feathers scarcely 
project half an inch. N. N. Am., ranging to the Middle States in winter ; not common. 
"766. 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 strife ; 
with a straight longitudinal sulcus on each side of the culmen. 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 sulcus 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 ; 
