294 Field Museum of Natural History — Zoology, Vol. IX. 



" Common migrant along the Lake, very rarely remains through 

 winter." (Nelson, Birds N. E. 111., 1876, p. 146.) A common migrant, 

 spring and fall. Formerly bred on Spider and Strawberry Islands, 

 Green Bay, from which localities we have eggs." (Kumlien and Hol- 

 lister, Birds of Wisconsin, 1903, p. 10.) 



18. Larus atricilla Linn. 



Laughing Gull. 



Distr.: Atlantic and Gulf coasts of United States, occasionally 

 north to Maine and even Nova Scotia; south in winter to West Indies, 

 Mexico, Central America, and northern South America. 



Adult in summer: Bill, dark red; head and throat, dusky black; 

 a white spot on each eyelid; outer primaries, brownish black; back, 

 slaty gray; under parts, white; tail, white. 



Adult in winter: Similar, but has the head and throat white, and 

 at times the crown and back of the neck streaked with gray. 



Immature: Bill, blackish; upper plumage and most of head and 

 neck, gray, mixed with pale buff; forehead, whitish; tail feathers, 

 gray, with broad, subterminal band of dark brown, and narrowly 

 tipped with white. 



The color and markings of the primaries and larger size will dis- 

 tinguish this species from Franklin's Gull. 



Length, 14.75 to 17; wing, 12.10 to 13.15; bill, 1.45 to 1.75. 



While rarely found in the interior, the Laughing Gull has been 

 given a place in the avifauna of both Illinois and Wisconsin. If 

 it occurs at all it must be considered an accidental straggler within 

 our limits.^ When not actually taken, its resemblance to Franklin's 

 Gull might lead to error in identification. 



" Very abundant on the Great Lakes." (Dr. Morris Gibbs, List 

 of Birds of Michigan, Bull. U. S. G. and G. Survey, No. 3, 1879.) 

 This is undoubtedly an error. "Summer visitant." (Ridgway, 

 An. N. Y. Lyceum Nat. Hist., 1874, p. 391.) "Probably only an 

 irregular or casual visitor to the Mississippi Valley." (Ridgway, 

 Orn. of Illinois, Vol. II, 1895, p. 234.) "A few pass up the Missis- 

 sippi during the summer as far as southern Illinois." (Cooke.) 

 " The only known Wisconsin record for this species is that of Thure 

 Kumlien, who shot a single specimen on Lake Koshkonong in July, 

 i860." (Kumlien and Hollistcr, Birds of Wisconsin, 1803, p. 10.) 



