398 
INSECTIVOROUS BIRDS. 
a small twig towards the extremity of the branches, and 
is formed of lichens and other materials, and lined with 
downy substances. The eggs, about 4, are white, with a 
few reddish dots at the larger end. The notes of this 
species resemble those of the Prairie Warbler in some 
respects, though sufficiently different ; the tones rising 
from low to high are rather weak and insignificant. 
This bird is from 4J to 5 inches long, and to 7 in alar extent. 
Above pale or dusky blue ; the head brightest. Wings and tail 
black, the former crossed with 2 conspicuous white bars and edged 
with blue. Between the bill and eyes black : above and below the 
eye a small touch of white. The upper mandible black ; the lower 
as well as the throat and breast bright yellow ; the latter deepening 
about its. middle into a brownish orange, and marked on the throat 
with a small crescent of blackish or dusky. On the edge of the 
breast, below the shoulder, is a cloud of bay. Belly and vent white. 
Legs and feet dull yellow. 
BLACK-THROATED BLUE WARBLER. 
(Sylvia canadensis , Lath. Wilson, ii. p 115. pi. 15. fig. 7. Phil. 
Museum, No. 7222.) 
Sp. Charact. — Slate blue ; beneath white ; cheeks and throat 
black ; a white spot on the wings ; 2 or 3 lateral tail-feathers 
with white on the inner web. 
Of this uncommon species we know very little. It 
appears only as a transient visitor in the month of April, 
in the Middle States, and, after staying to feed for a week 
or ten days, it proceeds to its northern breeding-place in 
the wilds of Canada, of which we are wholly ignorant. 
In November, I have observed a few on their return to 
the South, and, according to Vieillot, they winter in St. 
Domingo, and other of the larger West India islands. 
The length of this species is about 5 inches ; and in alar dimen- 
sions. Above wholly of a fine slate color, inclining to azure ; the throat, 
cheeks, and upper part of the breast, and sides under the wings, are 
