16 
U. S. P. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 
under surface of the body in the present bird never assume that degree of regularity which is 
commonly met with in the European bird, and it is in other respects quite distinct, as pointed 
out by the distinguished naturalists who have described it, Wilson and Temminck. 
List of specimens. 
Catalogue number/ 
Sex and age. 
Locality. 
When collected. 
Whence obtained. 
Original number. 
Collected by — 
Measurements. 
Length. 
Extent of wings. 
6906 
6846 
5839 
8508 
8509 
4365 
4518 
8507 
3 
3 
D. Gunn 
PortTownsend,W. T. 
FortSteilacoom.W. T. 
Jan., 1857 
Aug., 1856 
22.00 
22.50 
40. 00 
38.00 
do. 
528 
101 
306 
Governor Stevens 
Dr. Suckley 
do.. do 
Mar. 25, 1856. 
Shoal water Bay, W. T. 
Jan. 0, 1855 . 
Mar.b 1854.. 
120 
141 
Governor Stevens 

Dr. Suckley 
ACCIPITER, Br isson. 
Jccipiter, Brisson, Orn. I, 310, (1760.) 
General form more slender and smaller than Jlstur, but otherwise similar. Wings short, tail long, tarsi long and slender, 
frequently with the scales in front nearly obsolete. Contains about twenty species of all countries, several of which intimately 
resemble each other. Colors in North American species very similar to each other, especially in adult specimens, though they 
differ materially in size. 
ACCIPITER COOPERII, Bonaparte. 
Cooper's Hawk. 
Falco Cooperii, Bonap. Am. Orn. II, 1. (1828.) 
Falco Stanleii, Aud., Orn. Biog. I, 186. (1831.) 
Figures.— Bonap. Am. Orn. I, fig. 1 ; Aud. B. of Am. pi. 36, 141, fig. 3, ct. ed. 1, pi. 24. 
Jidult. Head above brownish black, mixed with white on the occiput, other upper parts dark ashy brown, with the shafts of 
the feathers brownish black ; an obscure rufous collar on the neck behind. Throat and under tail coverts white, the former with 
lines of dark brown, other under parts transversely barred with light rufous and white. Quills ashy brown, with darker bands, 
and white irregular markings on their inner webs ; tail dark cinereous, lipped with white, and with four wide bands of brownish 
black. 
Young. Head and neck behind yellowish white, tinged with rufous, and with longitudinal stripes and oblong spo of brown; 
other upper parts light amber brown, with large partially concealed spots and bars of white; upper tail coverts tipped with white; 
under parts white, with narrow longitudinal stripes of light brown, tail as in adult ; bill blueish horn-color ; tarsi yellow. 
Dimensions. — Female, total length 18 to 20 inches, wing 10 to 11, tail 8| inches ; male, 16 to 18 inches, wing 9| to 10, tail 
8 inches. 
Hub.— Ml of temperate North America. Chile (Gay). Spec, in Nat. Mus., Washington and Mus. Acad. Philadelphia. 
This species, rather common on the coast of the Atlantic, is apparently not so abundant in 
the western countries of the United States. Three specimens only are in the present collection, 
