LARID^E— THE GULLS AND TERNS. 239 



Sterna risoria Bbehm, Lehrb. 1823. 683; BeUr. Hi, 6B0. 



? Sterna macrotarsa Gould. Proo. Zool. Soo. Lond. pt. v, 18S7, 26; B. Austr. Suppl. 



Sterna affinis Hobsf. (flde Blas.). 



Gelochelidnn palustris Maogil. Man. li, 1842. 237. 



Oelochelidon balthica, agraria, meridionalis Beehm, Vog. Deutschl. 1831, 772. 773, 774. 



Hab. Nearly cosmopolitan, but in North Amerioaoonlned to the Eastern Province, and 

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

 of Central America; Bermuda? 



8p. Chab. Adult, in summer: Pileum and nape deep black ; upperparts, Inoluditisthe 

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

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

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

 plumage pure white. Bill wholly deep black; 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 erayish, as is also a crescentio space immediately in front of the eyes. 

 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 sufaoe; a blackish oresoentic spot Immediately in 

 front of the eye, and a dusky grayish suffusion on the aurioul&rs, forming a more or less 

 distinct posto'ular stripe. Ijower-parts entirely pure white. Bump, upper tail-coverts, 

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

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

 tipped with white or pale oehraoeous-buCt. 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 bufC, with several large and 

 tolerably well-defined dusky spots on the hind half of the head, most distinct on the latero- 

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

 and upper back; wings, rump, and flanks, with large,- ralher disllnst. spots of dusky. 

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

 the mandible more oi ange; legs and feet dull brownish orange. 



Total length, about 13.00 to 13.25 inches; extent, 33.00 to 37.50; wing, 11.75-12.25; tail, 6.50; 

 depth of fork, I.SU-1. 75; culmen, 1.40; depth of bill through base, .45; tarsus, 1.30; middle 

 toe, with claw, r.lO. 



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. 

 antiUa/rum), the Black Skimmer {Bynchqps nigra), and the Black- 

 headed Gull {Larm atricUla), in some localities outnumbering 

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

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

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

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

 or young, darting down at an intruder with such impetuosity, 

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

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



