78 TERNS. 



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



the head inclosing the eye 69. Forstee's Teen (Im.). 



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



over -TO 70. Commou Teen (Im.). 



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



under -70 71. Aectig Teen (Im.). 



£. W ing blackish, over 9-00. 



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



b. Under parts white 7C. Beidled Teen (Im.). 



4. Crown silvery gray ; lores black; rest of plumage sooty . 79. Noddy. 



C. Wing under 9-00 77. Black Teen (im.). 



II. Wing over 13-00. 



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

 M. Wing under 15-00 ; inner half of inner web of iirst primary white. 



65. KoYAL Teen. 



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

 (b) Eoyal Tern ; (c) Common Tern ; (d) Arctic Tern ; (e) Boseate Tern. 



63* Gelochelidon nilotica Ilasselq. 6nLL-BiLLSD Teen; Maesh 

 Teen. 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- 



