496 NORTH AMERICAN BIRDS. 
Adult male: Above dark dull blue, the back sometimes indis- 
tinctly spotted with black; sides of head, chin, throat, 
chest, sides of breast, and sides, uniform deep black; rest 
of lower parts white. (Jn winter, upper parts tinged with 
olive-green, the chin and throat varied, more or less, with 
white, and white of flanks tinged with brownish.) Adult 
female: Above plain dull olive or grayish green, sometimes 
tinged with blue; lower parts (including the portions 
which are black in the male) plain pale greenish buff. 
Young : Above dull brown, the wings (except coverts) and 
tail as in adults ; a dull yellowish white superciliary stripe; 
below this, sides of head blackish in male, dull grayish 
brown in female; lower parts yellowish white, more 
brownish anteriorly. Length 4.70-5.50, wing 2.50~2.65, 
tail 2.05-2.25. Nest on bushes in open coniferous woods, 
compact, composed of fine dry grasses, spiders’ webs, lichens, 
strips of fine bark, etc., the cavity 1.40 deep by 2.00 across. 
Eggs usually 4, .68 x .49, buffy whitish or greenish white, 
more or less heavily spotted or blotched with reddish brown. 
Hab. Eastern North America, breeding from northern New 
England and New York northward, and southward along 
higher Alleghanies; in winter, Florida, Bahamas, and 
Greater Antilles; accidental in California (Farallon Islands). 
654. D. czerulescens (GMEL.). 
Black-throated Blue Warbler. 
@. Outer surface of wings with more or less distinct lighter markings, 
but without white spot at base of quills. 
é. Rump yellow. 
#1, Crown with a yellow patch (partly concealed). 
g'. Adult male: Lower parts, including chin and throat, 
white, the chest and sides broadly streaked with 
black (these streaks sometimes more or less con- 
fluent, forming a broken patch), and the sides 
of the breast with a yellow patch; upper parts 
bluish gray, becoming blackish on sides of head, 
which are marked by white supraloral and post- 
ocular streaks ; back broadly streaked with black ; 
wing with two white bands across tips of middle 
and greater coverts. Adult female: Similar to 
male, but much duller in color, with markings 
less conspicuously contrasted. Winter plumage 
(sexes essentially alike): Upper parts strongly 
washed with umber-brown, and lower parts more 
or less suffused with a paler wash of the same— 
the pattern of the summer plumage being thereby 
