INDEX TO KEY. 



13 



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

 head marked with more or less white or grayish 

 white ; belly, mottled brown or grayish brown or 

 slaty . . . . 



Section 7. Hind toe, with well-defined membraneous lobe or flap ; 

 no white on head ; belly, mottled brown or grayish 

 brown ..... 



Group 6. Birds having wings from 12 to 14 inches long 



Section 1. Head, not black or marked with black 



Section 2. Head marked with more or less black, or entirely 



black ...... 



Group 7. Birds having wings from 14 to 19 inches long 



Section 1. Head and neck, black or blackish, usually marked 



with more or less white ..... 



Section 2. Head, white, sometimes tinged with brownish orange, 

 Section 3. Head, brownish or grayish, sometimes marked with 



white ......... 



Group 8. Birds having wings over 19 inches long 



30 



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32 

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32 

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33 

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35 

 36 



