266 KEY TO THE BIRDS OF EASTERN NORTH AMERICA. 
Tree Swallow. 
Entire underparts, white; upper plumage, metallic steel blue; young birds 
have the upper plumage brownish gray, but the under plumage is pure white. 
White-bellied Swallow. 
Tree Swallow. 
Tachycineta bicolor. 
See No. 462. 
Upper throat and sides of the head, chestnut 
brown; belly, whitish; forehead, whitish; 
crown and back, dark steel blue: upper tail 
coverts, pale rufous brown. 
Cliff Swallow. 
Petrochelidon lunifrons. 
See No. 458. 
Throat, chestnut; belly, pale browns entire 
upper plumage, steel blue; tail, forked; upper 
tail coverts, steel blue. 
Barn Swallow. 
Chelidon erythrogastra. 
See page 461. 
