BIRDS—BUTEONINAE—CIRCUS HUDSONIUS. 39 
Ficures.—Vieill. Ois. d’Am. Sept. pl. 9 ; Wilson Am. Orn. VI, pl. 51, fig. 2; Bonap. Am. Orn. II, pl. 12; Aud. B. of Am. 
pl. 356 ; Oct. ed I, pl. 26; Sw. & Rich. Faun. Bor. Am. Birds, pl. 29. 
Adult.—Form rather long and slender ; tarsi long ; ruff quite distinct on the neck in front. Entire upper parts, head and 
breast, pale bluish cinereous ; on the back of the head mixed with dark fulvous ; upper tail coverts white. Under parts white, 
with small cordate or hastate spots of light ferruginous ; quills brownish black, with their outer webs tinged with ashy, and a 
large portion of their inner webs white ; tail light cinereous, nearly white on the inner webs of the feathers, and with obscure 
transverse bands of brown ; under surface silky white ; under wing coverts white. 
Younger.—Entire upper parts dull umber brown, many feathers edged with dull rufous, especially on the neck ; under parts 
dull reddish white, with longitudinal stripes of brown, most numerous on the throat and neck before ; tibiae tinged with reddish ; 
upper tail coverts white. 
Young —Entire upper parts dark umber brown ; upper tail coverts white. Under parts rufous, with longitudinal stripes of 
brown on the breast and sides ; tail reddish brown, with about three wide bands of dark fulvous, paler on the inner webs. 
Tarsi and toes yellow. 
Total length, female, 19 to 21 inches ; wing 155, tail 10 inches. Male, total length 16 to 18 inches ; wing 14$, tail 84 to 9 inches- 
Hab.—All of North America and Cuba, (Mr. Lembeye.) 
Of this species, well known as one of the most common hawks inhabiting the States of the 
Atlantic, there are no less than fifty specimens in the collections made by the surveying and 
exploring expeditions. These were obtained, as will be seen below, at various points in the 
western States and Territories of the republic, and other localities in North America, and show 
conclusively that this species is equally abundant on the coasts of the Pacific as on those of the 
Atlantic ocean. It inhabits also, very probably, the entire intermediate country, and may, 
therefore, be regarded as diffused over the whole of North America from Mexico to the Arctic 
regions. 
Specimens from all parts of the United States are precisely the same specifically, and con- 
stantly present the entirely different colors of the adult and young birds. Several fine speci- 
mens of the former are in the present collection, all of which have the under parts nearly pure 
white, with more or less cordate and sagittate spots of reddish fulvous, varying considerably in 
size and number. One specimen, No. 5161, has those spots so large and numerous on the 
breast and sides that they give the predominating color to those parts. This specimen was 
obtained at Fort Randall, on the Missouri river, in October, 1856, by Lieutenant G@. K. Warren, 
United States army, and is marked as a female. The flanks and under tail coverts have also 
large cordate spots of the same color. 
