632 Field Museum of Natural History — Zoology, Vol. IX. 



Genus VIREOSYLVA Bonap. 



293, Vireosylva olivacea (Linn.). 

 Red-eyed Vireo. 



Vireo olivaceus (Linn.), A .0. U. Check List, 1895, p. 263. 



Distr.: North America, from. Colorado, Utah, western British 

 Columbia and Northwest Territory, eastward to the Atlantic coast; 

 breeds throughout its North American range; south in winter to 

 northern South America. 



Adult: Crown, gray, bordered by a black line; a whitish stripe 

 over the eye and a dusky stripe through the eye; back, olive green; 

 sides, olive green, rest of- under parts, white; wings and tail, slaty 

 brown, edged with greenish; iris, red. 



Sexes similar. 



Length, about 6; wing, 3.25; tail, 2.15; bill, .50. 



A common summer resident throughout Illinois and Wisconsin 

 from May until October. 



It breeds in May and June. The nest is a pensile structure, 

 finely made of shreds of bark, vegetable fiber, and plant down, and 

 is attached to a branch of a tree. The eggs are 3 to 4, white. 



