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ee. Primaries 9 or 10 ; if 10, outermost not two- 

 thirds as long as longest. 

 The great group of song-birds belongs under this head ; for 

 convenience we will divide it into two sections : those species 

 in which the front of the tarsus is covered by a number of 

 scales or long plates, and those in which these plates are fused 

 into a single sheath, a condition in which the tarsus is said to 

 be "booted." 



Section I. Tarsus not booted. 



1. Bill strongly hooked, and notched. 



A. Length over 8 inches. 



Beneath pure white, Loggerhead Shrike. 



Beneath white, with numerous fine transverse black 



lines, BUTCHEB-BIRD. 



B. Length under 7 inches. 



a. Throat bright yellow, Yellow-throated Vireo. 



aa. Throat not yellow, 

 b. Two white or yellow bars on wing. 



Iris brown ; head ashy with no yellow. 



Solitary Vireo. 

 Iris white ; head olive green with yellow. 



White-eyed Vireo. 

 bb. No bars on wing. 



Iris red ; crown black-edged, Eed-eyed Vireo. 

 Iris brown ; crown without black. 



Warbling Vireo. 



2. Bill not strongly hooked and notched, but nearly as broad 

 at base as long and with mouth extending under eyes. 



A. Plain brown above, 



A tuft of feathers at base of toes, Bank Swallow. 

 No such tuft. Rough-winged Swallow; 



