164 



TERNS 



II. Wing over 13'00. 



A. Wing 15'00 or over; outer primary mostly gray. 64. CASPIAN TERN. 



B. Wing under 15'00; inner half of inner web of first primary white. 



65. ROYAL TERN. 



FIG. 79. First primaries of adult Terns, seen from below: (a) Caspian Tern; 

 (6) Royal Tern; (c) Common Tern; (d) Arctic Tern; (e) Roseate Tern. 



63. Gelochelidon nilotica (Linn.}. GULL-BILLED TERN. Ads. in sum- 

 mer. Top of head and nape black; back and wings pale pearl-gray; outer 

 web of outer primaries silvery; tip and shaft part of inner web darker; 

 inner part of inner web, except for a narrow margin at end of feather, white ; 

 tail white, slightly forked, the middle feathers grayish; underparts white; 

 bill and feet black, the former rather short and stout. Ads. in winter. Sim- 

 ilar to the above, but top of the head white, auriculars grayish, and a space 

 in front of the eye blackish. L., 14'50; W M 12*00; T M 5'50; B., 1'40; depth of 

 B. at base, '50. 



Range. Nearly cosmopolitan. Breeds in N. Am. on coasts of Tex., 

 La., N. C., Va. (formerly to N. J.), and in the Bahamas; wanders casually 

 to Maine arid Ohio; winters in s. Mex., s. Guatemala, and from Brazil s. to 

 Patagonia and Chile. Breeds also in Europe, Asia, and Australia, and winters 

 s. to n. Africa. 



Washington, casual in autumn, no recent records. Long Island, A. V. 

 in summer. 



Nest, of shells and pebbles, on beaches. Eggs, 3-5, rather uniform buffy 

 white, with numerous distinct and obscure chocolate markings, 1*80 X 1'30. 

 Date, Corpus Christi, Tex., Apl. 30; Cobb's Is., Va., May 30. 



