U. S. p. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



List of e^ecimens. 



FALCO NIGRICEPS, Cassin. 



Falco nigriceps, Cassin, B. of Cal. and Te.xas I, p. 87. (1853.)— Ib. in Gilligg' U. S. Astron. Exped. II, 1855 

 pi. xiv. 



Resembling the preceding, but smaller and with the bill disproportionately weaker. Mull. — 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 

 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 

 Aull reddish yellow, paler on the throat, and with broad longitudinal/ 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 G}u 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 ahundant 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 bear more or less intimate relationship to 

 the Falco peregrinus of tlie 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. 



