8 U. 8. P. R. R. EXP. AND SURVEYS ZOOLOGY — GENERAL REPORT. 
List of specimens. 
logue No. 
Locality. 
When collected. 
Whence obtained. 
Collected by — 
Cata 
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. Astron. Exped. II, 1855 
pi. xiv. 
Resembling the preceding, but smaller and with the bill disproportionately weaker. Mult. — 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 circula r 
spots and transverse bands of black. Cheeks with a large space of black. 
Younger. — Upper plumage dark brown ; tail above brown, barred wi rufous on the inner webs of the feathers. Under part 
&ull reddish 3'ellow, paler on the throat, and with broad longitudina^ tripes 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 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 tbe collections made by the expeditions. 
This is one of the rather numerous species which bear 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. 
4307 
8501 
8500 
Locality. 
When collected. 
Puget's Sound, W. T. .. . 
Shoalwater Bay, W. T . . . 
Bodega, California 
Chile 
Sept. 26, 1854. 
Mar. 21, 1854. 
Jan., 1855 
Whence obtained. 
Dr. Suckley 
Governor Stevens.. 
Lieut. Trowbridge . 
Lieut. Gilliss 
Collected by — 
Geo. Gibbs--- 16.50 
Dr. Cooper... 17.50 
T. A. Szabo-.J 
Measurements. 
39.00 
30. 50 
