LARIDiE— THE GTTLL8 AND TERNS. 239 



Sterna risoria Brehm. Lehrb. 1823. 683; Beitr. iii, 650. 



? Sterna macrotarsa Gould. Proc. Zool. Soc. Lond. pt. v, 1837, 26; B. Austr. Suppl. 



Sterna affinis Horsf. (fide Blas.). 



Gelochelidon palustris Macgil. Man. ii, 1842, 237. 



Gelochelidon balthica, agraria, meridionalis Brehm, Vog. Deutschl. 1831, 772. 773, 774. 



Hab. Nearly cosmopolitan, but in North A.mericacon'1ned to the Eastern Province, and 

 rare away from the coast; the greater part of tropical America, south to Brazil: bothcoasts 

 of Central America; Bermuda? 



Sp. Char. A dull, in summer: Pileum and nape deep black: upper parts, including the 

 rump, upper tail-coverts, and tail, delicate pale pearl-gray, the primaries more hoary, and 

 usually darker; inner webs of primaries ash-gray, with a broad white space from the edge 

 more than half way to the shaft, but not extending to the ends of the quills. Rest of the 

 plumage pure white. Bill wholly deep blank; interior of mouth flesh-color; iris dark 

 brown ; legs and feet dark walnut-brown, the soles pale pinkish brown ; claws black. A dult, 

 in winter: Similar, but whole head and neck white, the nape tinged with grayish, the 

 auriculars darker grayish, as is also a crescentic space immediately in front of the eyf>8. 

 Young, first plumage: Above, pale pearl-gray, the feathers more or less tipped with 

 light clay-color, this sometimes almost uniform over the back and scapulars, where the 

 feathers are bluish only beneath the suface; a blackish crescentic spot immed'ately in 

 front of the eye. and a dusky grayish suffusion on the auriculars. forming a more or less 

 distinct postcular stripe. Lower parts entirely pure white. Rump, upper tail-coverts, 

 tail, and wing-coverts nearly uniform pale pearl-gray; remiges deeper silvery gray, the 

 secondaries and inner primaries tipped with white; recirices darker subterminally, and 

 tipped w : th white or pale oehraceous-buff. Pileum. back, and scapulars sometimes 

 streaked with dusky, oftener immaculate. Bi'l dusky brownish, the mandible dull orange- 

 brown, except terminally; legs and feet varying from dull reddish brown to dusky brown, 

 the soles more reddish. Downy young: Abov<», light grayish buff, with several la: ge and 

 to'erably well-defined dusky spots on the hind half of the head, most distinct on the latero- 

 occipital region; a distinct longitudinal stripe of dusky down each side of the lower nape 

 and upper back; wings, rump, and flanks, with large, rather distinst. spots of dusky. 

 Lower parts white, the sides of I he throat faintly tinged with grayish. Bill dull brownish, 

 the mandible more oiango; legs and feet dull brownish oiange. 



Total length, about 13.00 to 15.23 inches; extent, 33.00 to 37.50; wing, 11.75-12.25; tail, 5.50; 

 depth of fork, 1.50-1. 75; eulmen. 1.40; depth of bill through base, .45: tarsus, 1.30; middle 

 toe, with claw, 1.10. 



The Gull-billed Tern breeds abundantly along the Atlantic 

 coast of the United States, especially on the islands off shore, 

 which it inhabits in company with the Common Tern (S. 

 hirundo), Forster's Tern (S. forsteri), the Least Tern {S. 

 antiUarum), the Black Skimmer (Bynchops nigra), and the Black- 

 headed Gull {Zarm atricilla), in some localities outnumbering 

 any of the before-mentioned species. In those localities which 1 

 have visited its nest was usually placed on the dry Band, just 

 beyond reach of the surf, but not unfrequently at a considerable 

 distance from the shore. It is very hold in defence of its eggs 

 or young:, darting down ai an intruder with such impetuosity 

 as almost to strike him, scolding all the while with a harsh 

 chattering note, which may he compared to a discordant laugh. 



