78 



TERNS. 



II 



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



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



J2. Outer web of outer tail-feather darker tlian inner web; tarsus 



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



Js. 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 76. Bridled Tern (Im.). 



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



79. Noddy. 

 . Wing over IS'OO. 



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



B. Wing under 15-00 ; inner half of inner web of lirst primary white. 



65. KoYAL Tern. 



Fig. 61.— First primaries of adult Terns, seen from below. Co) Caspian Tern ; 

 (,6) Royal Tern ; (c) Common Tern ; [d) Arctic Tern ; (e) Roseate Tern. 



63. Gelochelidon nilotica Hasselq. Gull-billed Tern; Marsh 

 Tern. Ad. in, sum>/ier. — 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- 



