2. AixA. 567 



Alca Uaudica, Drehin, Ilandh. J'oy. Deutsrhl. p. 100'5, pi. xlvi. fig. 2 



(1831). 

 Alca niicrorliyneho.9, Brehm, Votjelf. p. 410 (1855). 

 Chenalopex torda, 6-'. R. Gray, Iland-l. li. iii. p. 95 (1871). 



A'hiU ill hreedht(i-plumage. General colour above smoky-black, 

 shadiug iuto sooty-brown on the sides of the face, chin, and throat ; 

 a narrow white stripe from the base of the culmen to the anterior 

 border of the eye ; fore-neck, chest, and rest of the underparts, 

 inchiding the under wing- and tail-coverts, pure white ; quills dark 

 brown, paler on the inner webs ; .secondaries tipped with white and 

 forming a narrow white band across the wing when closed ; tail 

 dark smoky-brown, wedge-shaped, and composed of 12 feathers. 

 Iris hazel ; bill black, with a transverse white band across both 

 mandibles ; between the white band and the tip one or two distinct 

 transverse folds ; feet black. 



Adult male. Total length about 17"5 inches, culmen from feathers 

 on forehead to tip 1"3-1*4, from gape to tip 1-9-2-1, greatest depth 

 of both mandibles at base 0-85, wing 7"2-7'3, tail 2-y-3, tarsus 

 1-25, middle toe and claw 1"8. 



Adult female. Total length about 17'0 inches, culmen from feathers 

 on forehead to tip 1-25, from gape to tip 2, greatest depth of both 

 mandibles at base O'S, wing 7*4, tail 3'3, tarsus 1"2, middle toe and 

 claw 1-8. 



Adidt in non-breeding plumage. Differs from the above in having 

 the chin, throat, cheeks, and sides of the head behind the eye 

 white, like the rest of the underparts, and the narrow white stripe 

 between the base of the culmen and the eye wanting. 



Young in down. Head, neck, and underparts covered with short 

 whitish down ; wings, sides, and flanks whitish buff ; rest of the 

 upper parts deep blackish-brown tipped with pale rufous. 



Nestling with Jirst plumage jiartlg developed. Closely resembles 

 the adult in breeding- plumage, the upper parts as well as the chin 

 and throat being dark smoky-brown, the white stripe between the 

 eye and the base of the bill clearly defined, and the rest of the 

 underparts white, slightly fringed with smoky-brown on the flanks. 



Young in first autumn plumage. Like the adult in winter, but 

 the bill is smooth, uniform black, and not nearly so deep. 



Young in second autumn plumage. Like the adult in winter 

 plumage, and has the transverse white stripes on the upper and 

 lower mandible clearly marked, but there are no transverse folds 

 between the white band and the tip of the culmen. 



Mab, The same as that of the genus. 



a, b. Ad. sk. North America, summer. Hudson's Bay Co. 



[P.]. 



c. Vix ad. sk. North America. Salvm-Godman Coll. 



d. 5 ad. sk. Woods Holl, Massachusetts, Salviu-Godman Coll. 



Dec. 15. 



e. Vix ad. sk. Mingan, Quebec, Canada, Salviu-Godman Coll. 



July L'O (C. U. Merriam). 



