SCIURIDA—SCIURUS HUDSONIUS VAR. RICHARDSONI. 677 
on the whole, rather more distinctly annulated with black below. Nova 
Scotia and Labrador specimens, as well as those from the different posts of 
the Hudson’s Bay Company and Alaska, have the hairs of the ventral surface 
very strongly annulated, and the dorsal band narrower and paler, often inclining 
strongly to fulvous. Specimens from the Upper Missouri, Yellowstone, and 
Black Hills are paler, and hence more fulvous, than those from east of the 
Mississippi. 
Var. RICIARDSONI. 
Richardson's Chickaree. 
VarieTaL Coars.—Length, from end of nose to base of tail, about 7.50; 
tail to end of vertebree about 5.90; to end of hairs 7.60. Above pale yel- 
lowish-gray; middle of the back dark brownish-red; beneath white, more or 
less distinctly annulated with black, as in northern examples of var. hudsonius. 
Generally, the gray of the dorsal surface is separated from the white of the 
ventral surface by a conspicuous black line. Tail centrally above like the 
middle of the back, with a broad subterminal bar of intense black faintly 
washed with yellowish-gray; often the terminal third is wholly black exter- 
nally; beneath, the tail is centrally reddish-gray, bordered with black faintly 
washed with yellowish-gray. ars black at the tip, bushy-tufted. Feet gen- 
erally of the same gray tint as the sides of the body, but sometimes reddish. 
The general color above varies from yellowish-brown to dark reddish- 
chestnut, with annulations of black. The rufous of the dorsal surface is 
generally strongest along the mesial line, where it frequently forms a broad 
dorsal band, which gradually passes into the color of the sides of the back. 
The black lateral line is generally well marked, often very prominent, even 
in winter specimens, but is occasionally wholly obsolete. The hairs of the 
tail are generally dark chestnut-red at the base, with a broad subterminal bar 
of black, and are tipped with yellowish-white. In some of the specimens, as 
those from Saint Mary’s, Rocky Mountains, the tail is almost wholly jet-black ; 
generally the -hairs are reddish, often dark reddish-chestnut at the base, 
with pale yellowish-gray tips. 
This variety appears to reach its extreme phase of development in the 
vicinity of Saint Mary’s and the Bitter Root Valley in the Rocky Mountains. 
Specimens from about Fort Benton and the eastern base of the Rocky 
Mountains in Montana and Northern Wyoming are less strongly marked, 
but generally incline more to this variety than to var. fremont? or than to hud- 
