152 BIRDS. 



9. STERNA, Linnaeus. COMMON TERNS. 



1. S. hirundo, Auct. COMMOX TERN. SEA SWALLOW. 

 WILSON S TERN. Bill red, blackening towards tip; tail 

 mostly white; outer web of outer feather darker than 

 inner; L. 144 (13 to* 16); W. 10 (94 to 11|); T. 6 (5 to 

 7.) Coasts of Europe and America; abundant. (/S. 

 iGilsoni) Lawr.) 



2. S. forsteri, Nuttall. FORSTER S TERN. Larger; 

 tail longer and wings shorter; inner web of outer tail 

 feather darker; W. 94 to 104; T. 6J to 8. N. Am., 

 common. 



3. S. macrura, Naumann. ARCTIC TERN. Bill carmine 

 throughout; plumage as in hirundo^ but darker below; 

 L. 14 to 17; W. 10 to 12; T. 5 to 8; smaller than 

 hirundo, but tail proportionally much longer. Northern 

 regions, S. to U. S. 



4. S. paradisea, Auct. ROSEATE TERN. Bill black, 

 usually orange at base below; mantle very pale; some 

 what rosy-tinted below; L. 12 to 1C; W. 9 to 10; T. 5 

 to 8. Atlantic Coast, abundant. ($. dougalli, Mont.) 



5. S. portlandica, Ridgway. PORTLAND TERN. Near 

 the preceding, but mantle as in hirundo; the rump 

 white instead of pearly; feet blackish; under parts pure 

 white; L. 12; W. 9; T. 5 or more. Lately discovered 

 in Maine and Mass.; but two specimens known. 



C. S. superciliaris, (Vieill.) var. antillarum, (Lesson) 

 Coues. LEAST TERN. Bill yellow, usually tipped with 

 black; a white frontal crescent between cap and bill; 

 shafts of two or more outer primaries black above ; very 

 small; L. 8 or 9; W. 6J; T. 2 to 84. U. S., chiefly 

 abundant coastwise. 



