78 TERNS. 



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



the head inelosing the eye 69. Fokstek's Teen (Im.). 



J>. Outer weh of outer tail-feather darker than inner web ; tarsus _ 



over '70 'if". Common Teen (Im.). 



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



under -TO 71- Arctic Teen (Im.). 



£. Wing blackish, over 9'00. 



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



h. Under parts white 76. Beidled Teen (Im.). 



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

 C. Wing under 9-00 77. BlacS^een (Im.). 



II. Wing over 13-00. 



A. Wing IS'OO or over ; outer primary mostly gray. 64. Caspian Teen. 



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



65. KoYAL Teen. 



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

 (6) Royal Tern ; (c) Commoa Tern ; (d) Arctic Tern ; (e) Roseate Tern. 



63. Gelochelidon nilotica Ifassdq. Gull-billed 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 inficr w?h darker ; inner part of the inuej- wpb, except for a nwrow mar- 



