178 
ARCTIC BLUE-BIRD. 
Length to end of tail 7 inches ; bill along the ridge along the edge of 
lower mandible R ; wing from flexure 4/^ ; tail 2’ r f ; tarsus ff , hind toe T 4 2 , 
its claw -,- 4 2 ; middle toe r \, its claw fb. 
Adult Female in summer. 
The female differs from the male in the same degree as that of the Arctic 
Blue-bird from its male ; the upper parts being light greyish-brown, tinged 
with blue, which is brighter on the rump ; the wings and tail are as in the 
male, but with less blue ; the lower parts are bluish-grey, the breast and sides 
light brownish-red, tinged with grey. 
ARCTIC BLUE-BIRD. 
Sialia ARCTICA, Swains. 
PLATE CXXXYI. — Male and Female. 
This beautiful species, first introduced to the notice of ornithologists by 
Dr. Richardsox, who procured a single specimen at Fort Franklin, in July 
1825, is merely a summer visitor to the Fur Countries. Both the male and 
the female are represented in my plate. The latter I believe has not hitherto 
been figured. Mr. Nuttall’s notice respecting this interesting bird, so 
closely allied to Sialia Wilsoni, is as follows : 
“ Sialia arctica. Ultramarine Blue-bird. About fifty or sixty miles 
north-west of the usual crossing place of that branch of the Platte called 
Larimie’s Fork, in the early part of June, this species of Sialia is not 
uncommon. The female utters a low plaint when her nest is approached, 
ihe place for which is indifferently chosen in a hole in a clay cliff, or in that 
of the trunk of a decayed cedar. At this time the young were hatched. 
The nest is made of the usual material of dry grass in very insignincant 
quantity. They are more shy than the common species, and have the same 
mode of feeding by watching on some low bush or plant, and descending for 
an insect. We afterwards saw a nest of this species on a cliff of the Sandy 
river, a branch of the Colorado of the West. The female and male were 
both feeding their brood. The former chirped and appeared uneasy at my 
approach, and at intervals uttered a plantive yeow. The male sings more 
