Yellow-billed Loon ji 
Adults in winter and young birds are brownish-black above and 
white below; the iris is brown and the bill is bluish-white, dusky 
along the culmen. The female is rather smaller than the male and 
the young bird has a markedly shorter bill. 
Distribution. Widely spread over the northern portion of both 
hemispheres, the Loon in America breeds from along the northern 
border of the United States northwards to Alaska, and Greenland, 
and winters throughout the States to the Gulfs of Mexico and Cali- 
fornia. In Colorado it is a rare migrant and is not yet known to winter 
or to breed, though it has been taken at Sweetwater Lake, Garfield 
co. in July (Cooke). There isan example from Barr Lake near Denver, 
killed in April by S. Wood, in the Denver Museum of Natural 
History, and another from near Boulder, collected by L. Bragg, 
now in the Museum of the University of Colorado, while Aiken tells 
me a good many specimens have reached him from time to time in 
spring. 
Yellow-billed Loon. Gavia adamsi. 
A.O.U. Checklist no 8—Colorado Record—Cooke 97, p. 155. 
Description.—Resembling G. immer, but slightly larger, and head 
a longer yellowish-horn bill, which is dusky only at the base ; the with 
and neck are steel blue rather than green, and the white spots on the 
upper-parts are rather larger, those on the scapulars being longer than 
broad instead of square. Length about 36:0; wing 15-0; culmen 3°50 
—3°75 ; tarsus 3°50. 
Distribution.—North-east Asia, Arctic America, from Behring 
Straits to Hudson Bay and north-west Europe, but hardly known in 
the United States. 
A young male Loon obtained by W. G. Smith near Loveland, May 
25th, 1885, and now in the collection of Mr. M. Hardy, Brewer, Me., 
has been identified with this rare Arctic form. This constitutes the 
only Colorado record. 
Black-throated Loon. Gavia arctica. 
A.O.U. Checklist no 9—Colorado Records—Cooke 97, p. 192; Aiken 
00, p. 298 ; Henderson 03, p. 234; 09, p. 225. 
Description.—Adult—Crown and nape grey ; rest of the upper-parts, 
including the throat and fore-neck glossy black, the sides of the neck, 
back and wings streaked, barred and spotted with white; a band of 
white streaks on the throat; rest of the under-parts white, 
with a band of blackish at the base of the under tail-coverts; iris 
red, bill and feet blackish. Length 27:0; wing 12:5; culmen 2°50; 
tarsus 2°90. 
