12 Birds of Colorado 
Adults in winter and young birds are dusky black above, the feathers 
of the back margined with greyish, giving a scaly appearance ; below 
white ; the neck slightly speckled with dusky ; iris brown, bill bluish- 
grey, feet dusky greenish. ; 
Distribution. Breeding in the northern parts of both hemispheres, 
in America only far north from Hudson Bay to Alaska; in winter 
south, casually but rarely to the northern borders of the United States. 
The Black-throated Loon is a rare winter visitor to Colorado. Three 
examples were killed on Prospect Lake, close to Colorado Springs, 
in November, 1898, and another near the same place in the fall of 1882 
(Aiken); an example in winter-dress obtained on Monument Creek, 
also close to Colorado Springs, November 5th, 1091, in the Aiken 
collection, is now preserved in the Colorado College Museum. 
Henderson considers his former record of this species too doubtful 
to be retained. 
ORDER LONGIPENNES. 
The members of this order, which includes the Gulls, 
Terns, Skimmers and Skuas, are chiefly marine forms, 
and are therefore not well represented in Colorado. 
They are all birds of medium size, with moderate- 
sized bills and simple, not tubular, nostrils ; the wings 
are long and consist of eleven primaries, the outer 
(twelfth) minute and hardly noticeable ; rectrices twelve 
in number, feet with the three front toes webbed, 
generally completely ; a small hind toe, not connected 
with the others, and jointed at a higher level, generally 
present. 
Kery oF THE Famities AND GENERA. 
A. Bill with a horny cere overhanging and partially concealing 
the nostrils (Stercorariide). Stercorarius, p. 13. 
B. Bill without cere (Laride). 
a. Bill stout, hardly as long as the head ; upper mandible longer 
than the lower, with the tip hooked down over it. 
at Tail square. 
a? Hind toe very small or absent, without claw. 
Rissa, p. 14. 
b? Hind toe present and clawed, though small. 
Larus, p. 15. 
