334 COLYMBIDAE, LOONS.—GEN. 311. 
of many feathers. Back spotted. Loons are large heavy birds with broad flattened 
body and rather long sinuous neck, abundant on the coasts and larger inland waters 
of the Northern Hemisphere ; they are noted for their powers of diving, being able 
to evade the shot from a gun by disappearing at the flash, and to swim many 
fathoms under water. They are migratory, breeding in high latitudes, generally 
dispersed further south in winter. They are priecocial, and lay two or three dark- 
colored spotted eggs in a rude nest of rushes by the water’s edge. The voice is 
extremely loud, harsh and resonant. The 9 is smaller than the ¢. There is but 
one genus, with only three well-determined species. 
311. Genus COLYMBUS Linnzus. 
Great Northern Diver, or Loon. Black; below from the breast white, 
with dark touches on the sides and vent; back with numerous square white 
spots; head and neck iridescent with violet and green, having a patch of 
sharp white streaks on each side of the neck and another on the throat ; 
bill black. Young: 
dark gray above, 
the feathers with 
paler edges ; below 
white from the bill, 
the sides dusky ; 
bill yellowish-green 
and dusky. Length 
24-3 feet; extent 
about 4; wing about 
14 inches; tarsus 3 
or more; longest 
toe and claw 4 or more; bill 3 or less, at base 1 deep and 3 wide; the 
culmen, commissure and gonys all gently curved. N. Am., abundant; 
the whole U. S. in winter. Wuus., ix, 84, pl. 74, f. 3; Nurr., ii, 513; 
AUD., Vii, 282, pl. 476; Lawr. m Bp., 888. .-- . “. 9.) 2 “©ToRQUATUS: 
Var. apamsit. Yellow-billed Loon. Similar; larger; spots on the back larger, 
not so nearly square ; gloss of the neck rather steel-blue, the white patches smaller, 
but the individual streaks larger; bill mostly yellowish-white, nearly 4 long, higher 
and comparatively narrower at the base, the gape straight, the culmen and gonys 
nearly so (fig. 215 shows the shape exactly, although intended for the common 
species). Northwestern America, chiefly; England; Asia. Gray, Proc. Zool. 
Soc. 1859, 167; Cours, Proc. Phila. Acad. 1862,.227; Extror, pl. 63. 
Black-throated Diver. Back and under parts much as in the last species ; 
upper part of head, and hind neck, bluish-ash or hoary gray; fore neck 
purplish-black with a patch of white streaks, the dark color ending abruptly ; 
bill black. The young resemble those of that species, but will be known 
by their inferior size. Length under 24 feet; extent about 3; wing 
13 or less; tarsus 3; bill about 24. N. Am. and N. Europe; said to be 
common and generally dispersed throughout the U.S. in winter, which is 
contrary to my experience. Sw. and Ricu., F. B.-A. ii, 475; Nurr., ii, 
D1; Aun, vu, 295, pl. 44 ¢; awe: in BD. 66.8. se 5-2) ARCTIONS: 
Fic. 213. Great Northern Diver. 
a 
