STERNA. 45 



niinal bar; lower rump and upper tail-coverts plum- 

 beous-gray, the longer feathers tipped with buff; ree- 

 triecs ]3ale bluish gru}', the feathers becoming duskj' 

 subterminully ; lower parts, except as described, white; 

 maxilla dusky, mandible light reddish (brownish in 

 di'ied skins), the terminal third or fourth dusky ; legs 

 and feet light reddish. Length 13.25-15.00, wing 

 9.75-10.75, tail G.50-7.00 (forked for 2.40-3.75), culmen 

 1.25-1.40, depth of bill at base .38, tarsus, .60-.75, ' 

 middle toe .80-.85. Eggs 1.G9 X 1-12, similar to those 

 of S. paradiscea, but averaging rather deeper in ground- 

 color, with larger markings. Hab. Eastern Aleutian 

 Islands and northward along coast to or beyond 

 Norton Sound. 



73. S. aleutica Baird. Aleutian Tern, 

 e'. Mantle and six to ten middle tail-feathers slaty or blackish. (Subgenus 

 Ualiplana Wagler.) 

 d}. Adult: Upper parts, including hind-neck, continuously uniform 

 Booty black, the outer pair of tail-feathers chiefly white; fore- 

 head, sides of head, and entire lower parts white, sometimes 

 faintlj' tinged with bluish gray posteriorly ; bill and feet deep 

 black. Young: Entirely dark sooty brown, more grayish on 

 lower parts, the anal region and under wing-coverts white ; 

 scapulars and wing-coverts narrowly but distinctly tipped with 

 white. Downy young: " Head, neck, throat, and entire upper 

 parts, dark gray with a silvery tinge, closelj- dotted with gray- 

 ish white; rest of under parts white." (Dresseu.) Length 

 15.00-17.00, wing 12.00, tail 7.00-7.50 (forked for about 3.00- 

 3.50), culmen 1.80, tarsus 1.00. Eggs (deposited on rocks or 

 ground, usually without nest) 2.02 X 1-40, white, creamy white, 

 or cream-color spotted with rich chestnut, usually mixed with 

 ftiinter spots of purplish gray. Hab. Tropical and subtropical 

 sea-coasts of both hemispheres; in North America, north to 

 the Carolinas and western Mexico, casuallj- to New England. 

 75. S. fuliginosa Gmel. Sooty Tern. 

 d'. Adult : Lower hind-neck and upper back grayish white, deepening 

 into brownish slate on wings, etc., and deep black on top of 

 bead ; forehead, sides of head, and entire lower parts pure 

 white ; two outer pairs of tail-feathers white ; bill and feet 

 black. Young: Entire lower parts, with cheeks, forehead, and 

 sides of crown, white, as in adult ; nape, occiput, and middle 

 of crown brownish dusk}-; the last streaked with grayish 

 ■white; upjjcr parts grajish brown; the scapulars, interscapu- 

 lars, and tertials margined terminally with grayish white. 

 Length about 14.00-15.00, wing 10.50, tail 0.00-7.00, culmen 



