32 NORTH AMERICAN BIRDS. 



h l . Bill with a black band near tip. 



Adult: Mantle pale pearl-gray (much as 

 in L. argentatus) ; bill greenish yellow, 

 crossed near end by a very distinct black 

 band, the tip sometimes tinged with 

 orange; iris pale yellow, eyelids vermil- 

 ion-red ; feet (in life) pale yellow, some- 

 times tinged with greenish. Young : 

 Above brownish dusky, the feathers 

 broadly bordered and otherwise varied 

 with pale grayish buff or dull whitish ; 

 quills blackish, the shorter ones bluish 

 gray basally and tipped with white ; tail 

 with basal half (or more) pale grayish, 

 the subterminal third (or more) blackish, 

 the tip narrowly white; lower parts 

 white, spotted along sides with grayish 

 brown; bill blackish, paler toward base. 

 Length 18.00-20.00, wing 13.60-15.75, cul- 

 men 1.55-1.75, depth of bill at angle .50- 

 .65, tarsus 1.90-2.45, middle toe (without 

 claw) 1.30-1.60. Eggs 2.39 X 1.71. Hob. 

 Whole of North America, breeding far 

 northward ; south, in winter, to Cuba 



and Mexico 54. L. delawarensis 



ORD. Ring-billed Gull. 

 W. Bill without black in adult. 



j 1 . Gray "wedge" on inner web of third 

 quill never tipped with white, and 

 not carried definitely farther than 

 tip of sixth, usually not much beyond 

 tip of seventh, quill. Adult : Mantle 

 pearl-gray (about intermediate in 

 shade between that of L. calif ornicus 

 % and L. argentatus) ; rest of plumage, 



except quills, pure white. Young: 

 Head and neck soiled whitish, striped 

 with grayish brown ; back, scapulars, 

 and wing-coverts dull grayish brown, 

 margined with grayish white ; basal 

 half of tail white, terminal half 

 blackish or dusky, narrowly tipped 

 with white ; lower parts dull white, 

 spotted and otherwise marked with 

 dull brown. Downy young: "Cov- 



