78 



TERNS. 



mostly or entirely white ; a black space generally on the side of 



the head inclosing the eye 09. Forster's Tern (Im.). 



Jfi. Outer web of outer tail-feather darker than inner web ; tarsus 



over -TO 70. Common Tern (Im.). 



h^. Outer web of outer tail-feather darker than inner web; tarsus 



under -70 71. Arctic Tern (Im.). 



B. Wing blackish, over 9-00. 



a. Under parts blackish 75. Sooty Tern (Im.). 



h. Under parts white 7<i. Bridled Tern (Im.). 



4. Crown silvery gray; lores black; rest of plumage sooty black. 



79. Noddy. 

 II. Wing over 13-00. 



A. Wing 15-00 or over ; outer primary mostly gray. 64. Caspian Tern. 

 £. Wing under 15-00 ; inner half of inner web of first primary white. 



65. KoYAL Tern, 



BMi.^agi^sjstji^^JW'jU 'jWjj j gjgu^^^ 



Fig. 61.— 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 Hassdq. Gull-billed Tern; Marsh 

 Tern. Ad. in summer. — Top of the head and nape black; back and wings 

 pale pearl-gray ; outer web of outer primaries silvery ; tip and shaft part of 

 the inner web darker; inner part of the inner web, except for a narrow mar- 



