INDEX TO KEY. 



11 



Group 3. Birds having wings between 7.50 and 8.50 inches long 18 



Section 1. Bill, narrow, with tooth-lUce serrations . 18 



Section 2. Bill, not narrow; hind toe, without mem- 

 braneous lobe or flap ; a patch of grayish 

 blue on shoulder (lesser and middle wing 

 coverts) . . . . . . 18 



Section 3. Hind toe, without membraneous lobe or flap ; lesser 



and middle wing coverts, not grayish blue . . 19 



Section 4. Hind toe, with well-deflned membraneous lobe or flap ; 

 head marked with more or less white or 

 brownish white ; belly, white, sometimes tinged 

 with dusky or gray on lower part . . . . 19 



Section 5. Hind toe, with well-defined membraneous lobe or flap ; 

 belly, white, sometimes tinged on lower part with 

 dusky or gray ; no white or grayish white on 



head 20 



Section 6. Hind toe, with well-deflned membraneous lobe or flap ; 



belly, not white ...... 20 



Group 4. Birds having wings from 8.50 to 10 inches long 21 



Section 1. Bill narrow, with tooth-like serrations . 21 



Section 2. Bill, not nar- 

 row ; hind toe, without 

 membraneous lobe or 

 flap; belly, white . ''^i^^^:'''^^^^:^ >^ 22 



Section 3. Hind toe, without membraneous lobe or flap ; belly, 



not white ........ 22 



