8 
U. 8. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
List of specimens. 
1 
Catalogue No. 
Locality.' 
When collected. 
Whence obtained. 
Collected by— 
5166 
Mouth of Vermilion river, Upper 
Missouri_______ 
October 25,1856. 
Lieut. G. K. Warren......... 
Dr. F. V. Hayden ..._... 
FALCO NIGRICEPS, Cassin. 
Falco nigriceps, Cassin, B. of Cal. and Texas I, p. 87. (1853.)— Ib. in Gilliss’ U. S. Aatron. Exped. II, 1855, 
pi. xiv. 
Resembling the preceding’, but smaller and with the bill disproportionately weaker. Adult .—Frontal band white, narrow 
Head and neck above black, tinged with cinereous; other upper parts bluish cinereous, with transverse bands of brownish 
black. Quills brownish black ; tail bluish cinereous, with transverse bands of black. Under parts reddish white, with circular 
spots and transverse bands of black. Cheeks with a large space of black. 
Younger .—Upper plumage dark brown ; tail above brown, barred with rufous on the inner webs of the feathers. Under part, 
dull reddish yellow, paler on the throat, and with broad longitudinal stripes of black ; flanks and under wing coverts with 
transverse bars and circular spots of reddish white. Bill bluish, legs and toes yellow. 
Total length 15 to 17 inches, wing 11 to 12, tail 6 to 6j^ inches. 
Hab. Western North and South America. Specimens in National Museum, Washington, and Museum Academy' 
Philadelphia. 
Like its relative of the eastern States of the Union, F. anatum, this species does not appear 
to he abundant on the western coast; or if so, like its eastern congener, it is not easily obtained. 
Three specimens only are in the collections made by the expeditions. 
This is one of the rather numerous species which hear more or less intimate relationship to 
the Falco peregrinus of the old world, and to Falco anatum of the United States. It is 
uniformly smaller than both, though most resembling the former, especially specimens from 
Asia. This bird is as yet known only as an inhabitant of the western countries of the continent 
of America from Oregon to Chi e. 
List of specimens. 
Catalogue number. 
Sex and age. 
Locality. 
When collected. 
Whence obtained. 
Original number. 
Collected by— 
Measurements. 
Point of bill to end 
of tail. 
Between tips of out¬ 
stretched wings. 
4307 
s 
Puget’s Sound, W. T. 
Sept. 26, 1854. 
Dr. Suckley..... 
183 
Geo. Gibbs ... 
16. 50 
39.00 
8501 
Shoalwater Bay, W. T_ 
Mar. 21, 1854. 
Governor Stevens.. 
63 
Dr. Cooper ... 
17.50 
30.50 
8500 
o 
T. A. Szabo_ 
V 
Lieut. Gilliss_ 
