JAN., 1909. BIRDS OF ILLINOIS AND WISCONSIN CORY. 



43 



Family LARID^. Gulls and Terns. 



Subfamily LARIN^. Gulls. 



Upper mandible, curved; unguis (end of bill), not swollen; nos- 

 trils, near middle of upper mandible ; middle tail feathers, about equal 

 in length to the others ; tail, rarely dark, although 

 sometimes tipped with black or brown; hind toe, 

 small, but always present except in one genus ; bill, 

 without cere. 



Glaucous Gull. 

 Herring Gull. 



Great Black-backed Gull. 

 Bonaparte's Gull. 



*GROUP 1. Wing, 9.50 to 11 inches long. 



Under parts, white; inner web of first primary, white, with black 

 spot near the end; the tip, white ; shaft of feather, white ; adult birds 

 have the bill dark red; in immature birds it is brownish. 



Larus franklinii. 

 Franklin's Gull. 

 See No. 19. 



* For directions for measurement, see page 21. 



