COCK OF THE PLAINS. 505 
oceasions stand erect. In this grotesque form he displays, in the pre- 
sence of his intended mate, a variety of attitudes. His love-song is a 
confused, grating, but not offensively disagreeable tone,—something 
that we can imitate, but have a difficulty in expressing—AHwrr-hurr- 
hurr-r-r-r-hoo, ending in a deep, hollow tone, not unlike the sound 
produced by blowing into a large reed. Nest on the ground, under 
the shade of Purshia and Artemisia, or near streams, among Pha- 
laris arundinacea, carefully constructed of dry grass and slender twigs. 
Eggs, from thirteen to seventeen, about the size of those of a com- 
mon fowl, of a wood-brown colour, with irregular chocolate blotches 
on the thick end. Period of incubation twenty-one to twenty-two days. 
The young leave the nest a few hours after they are hatched. In 
the summer and autumn months these birds are seen in small troops, 
and in winter and spring in flocks of several hundreds. Plentiful 
throughout the barren, arid plains of the river Columbia; also in the 
interior of North California. They do not exist on the banks of the 
River Missouri; nor have they been seen in any place east of the 
Rocky Mountains.” 
Terrao Uroruasianus, Ch. Bonap. Amer. Ornith. vol. ili. pl. 21, fig. 1. Female. 
TetTrRao (CenTRocERcus) Urnornasianus, Richards. and Swains. Fauna Bor.-Ame- 
ricana, vol. ii. p. 358. 
Cock of the Piatns, Nuttall, Manual, vol. ii. p. 665. 
Adult Male. Plate CCCLXXI. Fig. 1. 
Bill shortish, strong, somewhat compressed ; upper mandible with 
the dorsal line arcuato-declinate, the ridge flattened at the base and 
narrowed on account of the great extent of the nasal sinus, which is 
feathered, the sides convex toward the end, the edges inflected, the tip 
narrow and rounded ; lower mandible with the angle of moderate length 
and width, the dorsal line ascending and convex, the edges sharp and 
inflected, the tip obtuse, but like the upper thin-edged. Head rather 
small, oblong ; neck of moderate length ; body full. Feet rather short, 
stout; tarsus roundish, feathered, bare and reticulated behind. Toes 
of moderate size, covered above with numerous scutella, laterally pec- 
tinated with slender projecting flattened scales ; first toe small, second 
a little shorter than fourth, third much longer. Claws stout, slightly 
arched, moderately compressed, obtuse. 
