KEY TO T[IE \\'ATI:k IUKDS OI" !• LOR IDA. 



■f:) 



SuBFAMiEv STERNIN.-E. I^krns. 



-=/ 



Sterna maxima. 



Sterna fuliginosa. 



Length, 21; Wing, 16; Tail, 6.10: Tarsus, 1.80 ; 

 Bill, 3. Bill «leex> red ; primaries dark slate 

 color on inner webs. 



Length. 19: Wing, 14; Tail, 7.10: IJill. 2.40. Bill 

 orange or yellow ; back pearl gray ; under parts 

 white. 



Length, 17; Wing, 11.50; Tail, 7.20; Rill, 1.70. Bill 

 black ; l)ack and upper parts brownish black ; 

 under parts white. 



Length. 15. 50; Wing, 12.25 ; Tail, 5.60; r)ill. 2.10. 

 Bill black tipped with yellow ; back pearl gray; 

 under parts white. 



Length, 15; Wing, 10.30: Tail. 5.50; Bill, 1.45; Tar- 

 sus, .70 to .So. Adult in suninier — Bill red tipped 

 with black; feet red ; under parts ashy. Adult 

 in winter — under parts white : bill brownish l)lack; 

 Outer web of outer tail feather darker than 

 inner web at all seasons. 



Sterna tschegrava. 

 Caspian Tern. See page 194 



Sterna maxima. 



Royal Tern. .See page 195 



Sterna fuliginosa. 



Sooty Tern. See page 19S 



Sterna sandvicensis acuflavida. 

 Cabot's Tern, See page 195 



Sterna hirundo. 



Common Tern. See page 196 



