528 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



66. Back and scapulars partly dusky brown or grajdsh brown, the feathers mar- 

 gined with buffy whitish or cinnamon. ( Young.) 

 c. Rump gray or grayish brown, like back. 



d. Larger; general color of upper parts much paler. 



Hydrochelidon leucopareia, young (p. 529). 

 dd. Smaller; general color of upper parts much darker. 



Hydrochelidon nigra nigra, young (extralimital). 



Hydrochelidon nigra surinamensis, young (p. 533). 



ct. Rump white Hydrochelidon leucoptera, young (p. 537). 



HYDROCHELIDON LEUCOPAREIA (Tenmiinck).a 



WHISKERED TERN. 



Adults in summer (sexes alike). — Pileum and nape, including 

 greater part of lores and upper portion of auricular region, uniform 

 black; rest of upper parts plain light gray (between neutral gra}^ and 

 light neutral gray, slightly more bluish than light quaker drab), 

 sometimes slightly paler on wing-coverts or darker on back and 

 hindneck, the outer webs of primaries Ughter and more silvery gray; 

 lateral rectrices paler gray than middle pair, fading into white 

 basally; lower portion of lores, suborbital region, greater part of 

 auricular region, post-auricular region, and anterior portion of 

 malar region, immaculate white; chin, throat, and posterior half or 

 more of malar region very pale gray (almost grayish white on chin), 

 deepening on neck, aU round, and chest into a gray like that of upper 

 parts, this gradually deepening on abdomen, sides, and flanks into 

 deep purplish gray (deep quaker drab or purplish dark quaker drab) ; 

 under wing-coverts, under tail-coverts, and anal region immaculate 

 white; inner webs of primaries mostly white, the portion next to 

 shaft gray; bill deep red; iris dark brown; legs and feet vermilion red 

 (in life). 



Adults in winter. — Forehead, crown, and occiput white, streaked, 

 except on forehead, with blackish, the nape nearly uniform black; 

 sides of head (beneath eyes), neck (all round), and entire under parts 

 immacidate white; lores white, flecked with dusky in front of eyes; 

 otherwise like summer adults, but bill and feet duller red or reddish 

 brown. 



« This species is divided by Mathews (Birds of Australia, ii, pt. 3, Sept. 20, 1911, 

 pp. 321-323) into eight subspecies, as follows: 



(1) H. leucopareia leucopareia (Temminck). (Southern and central Europe; north- 

 em Africa.) 



(2) H. leucopareia indica (Stephens). (Northern India.) 



(3) H. leucopareia leggd Mathews. (Ceylon.) 



(4) H. leucopareia delalandii (Bonaparte). (Southern Africa.) 



(5) H. leucopareia swinhoei Mathews. (China.) 



(6) n. leucopareia javanica (Horsfield). (Java, etc.) 



(7) II. leucopareia fluviatilis (Gould). (Eastern and southern Australia.) 



(8) n. leucopareia rogcrsi Mathews. (Northern and northwestern Australia.) 

 Owing to lack of sufficient material bearing on any of these supposed forms I am 



not prepared to express an opinion as to their validity. 



