BLACK - THROAT ED GREEN WARBLER, 
185 
more of a dusky ash on the breast ; and in some specimens nearly 
■white. 
They no doubt pass this way on their return in autumn, for I have 
myself shot several in that season ; but as the woods are then still 
thick with leaves, they are much more difficult to be seen ; and make a 
shorter stay than they do in spring. 
Species XV. SYLVIA VIRENS. 
BLACK-THROATED GREEN WARBLER. 
[Plate XVII. Fig. 3.] 
Motacilla virens, Gmei,. Sffst. i., p. 985.—LeJiguier dcravate noire, Buff, v., p. 298. 
— Black-throated Green Flycatcher, Edh'. t. 300. — Green Warbler, Arct. Zool. u., 
No. 297. — Lath. Syn. iv.. p. 484, 108. — Turton, Syst. p. GOT. — Pants viridis 
gutture nigro, the Green Blaclc-throated Flycatcher, Bartram. p. 292* 
This is one of those transient visitors that pass through Pennsylva- 
nia, in the latter part of April and beginning of May, on their way 
to the north to hreed. It generally frequents the high branches and 
tops of trees, in the woods, in search of the larv® of insects that prey 
on the opening buds. It has a few singular chirrupping notes ; and is 
very lively and active. About the tenth of May it disappears. It is 
rarely observed on its return in the fall, which may probably be owing 
to the scarcity of its proper food at that season obliging it to pass with 
greater haste ; or to the foliage, which prevents it and other passengers 
from being so easily observed. Some few of these birds, however, remain 
all summer in Pennsylvania, having myself shot three this season, in 
the month of June ; but I have never yet seen their nest. 
This species is four inches and three quarters long, and seven broad ; 
the whole back, crown and hind head is of a rich yellowish green ; front, 
cheeks, sides of the breast, and line over the eye, yellow ; chin and throat 
black ; sides under the wings spotted with black ; belly and vent white ; 
wings dusky black, marked with two white bars ; bill black ; legs and 
feet brownish yellow ; tail dusky edged with light ash ; the three exte- 
rior feathers spotted on their inner webs with white. The female is dis- 
tinguished by having no black on the throat. 
* Sylvia virens, Vieill. Ois. de I' Am. Sept. pi. 80. 
