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SPOLIA ZEYLANICA. 
Back gray. 
A.—Large size; wing over 11°5 inches; tarsus 
blackish. 
(a) Bill black ; wing 12°5 inches. 
Sterna anglica (Gull-billed Tern). 
(b) Bill yellow, under 3 inches; wing 12 inches. 
Sterna media (Smaller Crested Tern). 
(c) Bill yellow, about 3°5 inches; wing 
14 inches or over. 
Sterna bergii (Large Crested Tern). 
B.—Medium size ; wing 8 to 11°5 inches. 
(a) Bill yellow and stout; legs red; wing 
11 inches. 
Sterna seena (Indian River Tern). 
(b) Bill orange-yellow and slender; legs 
orange-red ; wing 9 inches. 
Sterna melanogaster (Black-bellied Tern). 
(c) Bill coral-red in summer, duller in winter, 
about 2 inches; legs and feet same 
colour as bill. 
Sterna fluviatilis (the Common Tern). 
(d) Bill black always, about 1°75 inches; 
legs and feet blackish. 
Sterna longipennis (Nordmann’s Tern). 
(ec) Bill orange-red, black at the tip; legs 
and feet scarlet; outer tail feathers 
practically all white. 
Sterna dougalli (Roseate Tern). 
C.—Small size ; wing about 7 inches. 
(a) In adults shafts of all primaries, in young 
shaft of first primary, white. 
Sterna sinensis (White-shafted Ternlet). 
(6) Shaft of first three primaries blackish. 
Sterna saundersi (Black-shafted Ternlet). 
