768 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
CICERONIA PUSILLA (Pallas). 
LEAST AUKLET. 
Adults in breeding season (sexes alike).—Upper parts slate-blackish 
(sometimes inclining to glossy black), passing into dark slate color 
on suborbital and malar regions and chin, the scapulars intermixed 
with more or less of white, the proximal secondaries (sometimes 
proximal greater coverts also) more or less distinctly tipped with 
white; acuminate feathers on forehead and lores, and elongated 
acicular rictal and auricular plumes white; under parts mostly 
white, more or less spotted or blotched with blackish or blackish 
slate, this frequently forming a distinct and uninterrupted band, of 
variable width, across foreneck, usually in abrupt contrast anteriorly 
with the immaculate white of throat; axillars and under wing-coverts 
white and pale gray; bill dusky basally, dark reddish terminally ; 
iris white; legs and feet brownish (pale bluish in life ?). 
Winter plumage.—Similar to the summer plumage, but under 
parts, including sides of neck, continuously white, the chin, however, 
slaty, as in summer; white acicular feathers of forehead, etc., 
usually less developed, often (in younger birds?) wanting; bill 
without the knob at base of culmen. 
Young.—Similar to the winter adult but bill smaller; no trace of 
acicular white feathers on head, but with more white on scapulars. 
Downy young.—Entirely plain dark sooty grayish brown, the 
under parts paler and more grayish. 
Adult male—Wing, 90-97.5 (92.9); tail, 25.5-29 (27.1); exposed 
culmen, 8-9 (8.6); tarsus, 17-19.5 (18.3); middle toe, 20-24 (22.1).° 
Adult female.—Wing, 88.5-96 (93.6); tail, 24.5-29 (27.5); exposed 
culmen, 7.5-9.5 (8.5); tarsus, 16-19 (18.2); middle toe, 20-23.5 
(21.9).¢ 
Coasts and islands of Bering Sea and contiguous portions of 
northern Pacific Ocean; breeding on islands in Bering Sea (Diomede, 
St. Lawrence, King or Okewuk, and Pribilof islands), and Aleutian 
chain; in winter, coast of eastern Siberia (Plover: Bay; Usuri Bay; 
Cape Iksurus), Commander Islands, Kuril Islands, northern Japan 
(Hakodate), Okotsk Sea, and along North American coast as far 
southward as Washington (Tacoma, winter of 1888); casual or 
accidental at St. Michaels and Point Barrow, Alaska. 
Uria pusilla Pattas, Zoogr. Rosso-Asiat., ii, 1826, 373, excl. synonymy, pl. 70 
(Kamchatka). ' 
Phaleris pusilla Cassin, in Baird, Rep. Pacific R. R. Surv., ix, 1858, 909; Proc. 
Ac. Nat. Sci. Phila., 1862, 324 (Bering Straits)—Barrp, Cat. N. N. Am. 
Birds, 1859, no. 723.—Cornp#, Rev. et Mag. de Zool., 1860, 403 (St. Paul 
Island, Pribilofs)—Extror, Illustr. New and Unfig. N. Am. Birds, pt. 6, 
1867 (vol. ii, 1869), pl. 68 and text.—Da.u and Bannister, Trans. Chicago 
@Ten specimens (mostly from Pribilof Islands, Alaska). 
