152 BIRDS. 



9. STERNA, Linnfens. ComaiOx Terxs. 



1. S. hirundo, Auct. Common Tern. Sea Swallow. 

 Wilson's Tern. Bill red, blackening towards tip; tail 

 mostly white; outer web of outer feather darker than 

 inner; L. 14^ (13 to 16); W. 10 (9^ to 11|); T. 6 (5 to 

 7.). Coasts of Europe and America; abundant. (aS'. 

 ivilsoiiiy Lawr.) 



2. S. forsteri, Nuttall. Forster's Tern. Larger; 

 tail longer and wings shorter; inner web of outer tail 

 feather darker; W. 9^ to 10^; T. 6^ to 8. N. Am., 

 jommon. 



3. S. macrura, Naumann. Arctic Tern. Bill carmine 

 Aroughout; 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. dougalli, Mont. Roseate Tern. Bill black, 

 usually orange at base below; mantle very pale; some- 

 what rosy -tinted below; L. 12 to 16; W. 9 to 10; T. 5 

 to 8. Atlantic Coast, abundant. {^S. dougalji^ Mont.) 



5. S. portlandica, Ridgway. Portland Tern. Near 

 the preceding, but mantle as in hirundoj the rump 

 white instead of pearly; feet blackish; under parts pure 

 \Ahite; L. 12^; W. 9|; T. 5 or more. Lately discovered 

 in Maine and Mass.;. but two specimens known. 



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

 Cones. 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. 6^; T. 2 to 3^. U. S., chiefly 

 abundant coastwise. 



