DENDROICA. Uy | 
yellow, margined with black, instead of black margined with white. 
The heads are very differently marked. To D. dominica there is a 
strong resemblance, except that the infra-ocular crescent and eyelids 
are yellow, not white; the black of sides of head is much less ex- 
tensive, and without the conspicuous white patch behind it. There 
is much more white on the tail; the back is streaked with black; the 
bill is shorter and straighter, and the size much less. 
The relationship to D. adelaidx, Baird, is much closer, however, 
than to any other species. The proportions are rather different— 
the wings, tail, and toes being considerably longer; the bills pre- 
cisely similar. The coloration and marking of the upper parts, and 
of the head, are almost precisely the same, perhaps even to the 
dorsal streaks, very obsoletely visible in the winter specimens of 
adelaide. The yellow, however, of the under parts does not ex- 
tend beyond the jugulum, where it is abruptly defined, instead of 
spreading over the whole under parts, excepting perhaps the crissum. 
D. adelaide, too, lacks the conspicuous black streaks of the sides 3 
and the white of the outer tail feather is merely a quadrate patch in 
the terminal half of the inner web, 
This species appears to be abundant in Arizona, not less than ten 
specimens having been collected by Dr. Coues, though mostly in 
very indifferent plumage, owing to the season. 
Of the four species, just referred to, the D. nigrescens is readily 
distinguished by the black chin and throat ; the diagnostic characters 
of the other three will be as follows :-— 
Common CHARACTERS.—Upper parts ash gray, the forehead and 
sides of vertex black. A line from nostril to above eye 
(passing into white behind), chin, and throat, yellow, mar- 
gined laterally with blackish; crissum, inside of wings, 
axillars, and two bands on wing, white. 
Superciliary line extending to the nape, and white, except- 
ing anterior to the eye. Cheeks black, separated from 
the ash of the neck by a white patch. Eyelids and 
infra-ocular crescent white. Back not streaked. Bill 
lengthened, gonys almost concave. 
Yellow confined to jugulum; rest of under parts 
white; the sides streaked with black . . dominica. 
Superciliary line scarcely extending beyond the eye, and 
yellow, excepting at extreme end. Cheeks ashy, like 
sides of neck; dusky only near the eye, and not bor- 
dered on side of neck behind by white. Eyelids and 
infra-ocular crescent yellow. Lack streaked. Bill 
short, gonys slightly convex. 
