FAMILY LAKIDyE. — CULLS AND T?:RNS. 43 



Outer web of outer tail feather, darker than inner web; back, pearl j?ray ; breast 

 ami uiiiitTiiarl-;, iicarl liiay : l>ill, in adults, oiitirely red; tarsus, usually less than .70. 



Stoma paradiswn. Arctic Tern. 

 See No. 46. 



Rack, black; a white stripe from forehead, extending over the eye; breast, white; bill, 

 hi adults, black. Stfr)i(c fnfiijinosa. Sooty Tern. 



See No. 4!t. 



Rack, .sooty or grayish brown; a white stripe from forehead, not reaching above the 

 eye; l)ill, black. Sterna anvethctus. Bridled Tern. 



See Xo. no. 



Back, sooty brown; underparts, sootj' brown. Anous stolidus. Noddy Tern. 



See \o. 58. 



* Group 5. Wing, 11 to 13 inches long. 



Hill, black, not tipped with yellow; feet, blackish; back, pearl gray ; bill, comparatively 

 short and stout. GelocheUdon nilotica. Gull-billed Tern. 



See No. 39. 



Hill, black, not tipped with yellow; feet, black; back, black or sooty. 



Sterna ftdiginosa. Sooty Tern. 

 See No. 4it. 



Bill, red, tipiied with Itlack; feet, ()nini:;e red; back, pearl gray or gray and bull". 



Sterna hirundo. Common Tern. Wilson's Tern. 



See No. 43. 



Bill, black, tipped vvith pale yellow; feet, dark; bill, comparatively long and slender. 



Sterna sandvicensis acnflavida. Cabot's Tern. 



See No. 39. 



" Group 6. Wing, 13 to 17 inches long. 



Bill, orange or yellowish; tarsus, less than l..">0; inner web of outer primary, usually ^ 

 with more or less white. Sterna maxima. Royal Tern. 



S«e No. 4l. 



Bill, red or reddish; tarsus, over 1.50; iuuer web of outer primary, usually without 

 ^ hire. Sterna raspia. Caspian Tern. 



See No. 40. 



Bill, black, tipi)ed with yellow. Sterna sandvicensis acnflavida. Cabot's Tern. 



See No. 39. 



* Group 7. Wing, over 17 inches, long. 



Bill, red or reddish. Sterna caspia. Caspian Tern. 



See No 40. 



* For directions for measurement, see page 9. 



