STERNA. 45 



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

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

 trices pale bluish gray, the feathers becoming dusky 

 subterminally ; lower parts, except as described, white; 

 maxilla dusky, mandible light reddish (brownish in 

 dried skins), the terminal third or fourth dusky ; legs 

 and feet light reddish. Length 13.25-15.00, wing 

 9.75-10.75, tail 6.50-7.00 (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 1.69 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. 

 c^. Mantle and six to ten middle tail-feathers slaty or blackish ; inner webs 

 of quills entirely dusky. (Subgenus Haliplana Wagler.) 

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

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

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

 faintly 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, closely dotted with gray- 

 ish white ; rest of under parts white." (Dresser.) 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 

 fainter spots of purplish gray. Hab. Tropical and subtropical 

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

 the Carolinas and western Mexico, casually to New England. 



75. S. fuliginosa Gmel. Sooty Tern. 

 d^. Adult : Lower hind-neck and upper back gi'ayish white, deepening 

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

 head ; 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 dusky ; the last streaked M^ith grayish 

 white ; upper parts gi'ayish brown ; the scapulars, interscapu- 

 lars, and tertials margined terminally with grayish white. 

 Length about 14.00-15.00, wing 10.50, tail 6.00-7.00, culmen 



