224 
U. S P. B. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 
List of specimens. 
Sex. 
3 
3 
3 
Locality. 
When collected 
Whence obtained. Orig'l 
No. 
Collected by- 
Length. 
Stretch 
ofwings 
Wing. 
Remarks. 
Port fiteilannnm. W. T.. J Anril 17.1856 
6.75 
7.75 
13.0 
12.50 
Gov. Stevens 
114 
77 
274 
273 
4.00 
4.00 

6.75 
7.50 
12.00 
12. 
do 
Fort Vancouver, W. T. . 
Columbia river, 0. T. ... 
3 
Q 
3 
9 
3 
g 
S. F. Baird 
May 9, 1856 
170 
do 
Santa Clara, Cal 
Nov., 1855. ... 
Winter of '55 & '6 
12.00 
Q 
3 
Lt. R. S.Williamson 
Gila river, New Mexico.. 
24 
24 
151 
Fort Fillmore, N. Mexico. 
Mimbrcs to Rio Grande 
Oct. £1, 1855 
7.00 
12.50 
4.50 
Bill and eye 
black ; gums 
yellowish. 
Organ Mts., New Mexico. 
Mar. 9, 1856 
178 
7.00 
13.00 
4.25 
Bill, feet, and 
eyes black ; 
gums bluish. 
Camp 110, New Mexico.. 
Jan. 31, 1854 
Lieut. Whipple .... 
60 
4.00 
Fort Conrad, New Mexico. 
Saltillo, Mexico 
Oct., 1853 
Lieut. Whipple.... 
52 
.75 
4.50 
Q 
11.50 
Bill &. ft. black. 
SIALIA ARCTICA, Swain son. 
Rocky Mountain Blue Bird. 
Erylhraca (Sialia) arctica, Swainson, F. Bor. Amer. II, 1831, 209 ; pi. xxxix. 
Erylhraca arctica, Rich. List, 1837. 
Sialia arctica, Nuttall, Man. II, 1832, 573 ; I, 2d ed., 1840, 514.— Bonap. List, 1838.— Aud. Synopsis, 1839, 84.— 
Ib. Birds Amer. II, 1841, 178 ; pi. 136.— McCall, Pr. A. N. Sc. V, June, 1851, 215. 
Sylvia arctica, Audubon, Orn. Biog. V, 1839, 38 ; pi. 373. 
Sialia macroptera, Baird, Stansbury Report Exp. Salt Lake, 1852, 314. 
Sp. Ch. — Azure blue above and below, brightest above ; the belly and under tail coverts white : the latter tinged with blue 
at the ends. Female showing blue only on the rump, wings, and tail ; a white ring round the eye ; the lores and sometimes a 
narrow front whitish ; elsewhere replaced by brown. Length, 6.25 ; wing, 4.36 ; tail, 3.00. (1875.) 
Hab. — High dry central plains ; Upper Missouri to Rocky mountains range and south to Mexico. Rare on the coast of 
California. 
In this species there is none of the reddish hrown of the two other American blue birds, the 
color throughout being blue, except as mentioned. The shade of blue is much lighter, with 
more green in it, or smalts-color, especially on the crown, instead of the purplish blue of the 
others. The shade on the under parts is paler than above ; it extends entirely along the sides 
and to the abdomen. 
The female has the abdomen and under coverts like the male ; the remaining under parts, 
with the head, neck and back, are light brown, although a bluish shade is appreciable on 
