682 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
ever, is much browner. Specimens without the dorsal band, and with more 
black in the tail, also so approach var. fremonti as to be as well referable to 
this as to var. hudsonius. Some of the Uintah Mountain specimens also pre- 
sent a decided approach toward var. richardsoni. 
GENERAL REMARKS RESPECTING SCIURUS HUDSONIUS AND ITS VARIETIES. 
DIFFERENTIAL CHARACTERS AND AFFINITIES.—The four subspecies of Sc?- 
urus hudsonius, namely, hudsonius,richardsoni,douglassi, and fremonti, are gener- 
ally readily distinguishable by their coloration, especially by the markings of the 
tail. In respect to size, var. hudsonius, as represented in the United States, 
is rather smaller than either of the others, but examples from Alaska and 
British North America equal the largest specimens of the other varieties. 
Vars. richardsoni, douglassi, and fremonti do not differ materially in size. All 
the varieties except fremonti have usually a more or less distinct reddish 
band along the middle of the back, which extends from the top of the head 
nearly to the end of the tail. This, in var. hudsonius, is yellowish-red; in vars. 
richardsoni and fremonti, it is of a much darker tint, generally dark brownish- 
red. All are white or grayish-white below, except var. douglassi, which has 
the ventral surface fulvous or buffy. The northern representatives of the 
three northern varieties (hudsonius, richardsoni, and douglassi) are generally 
finely annulated on the ventral surface with black; in their southern repre- 
sentatives and in var. fremonti, these annulations are generally absent. The 
dorsal surface in all is finely annulated with black, the general color varying 
from fulvous to rufous-gray. A conspicuous black lateral line is more or less 
prevalent in all, especially in summer, and particularly among young specimens 
of var. hudsonius. In winter, it is frequently, if not generally, absent in all, 
and in var. hudsonius almost invariably so; late in autumn, it is generally 
obscure. 
Var. hudsonius is distinguished by its lighter and more fulvous tints, 
being above generally pale yellowish-gray vr grayish-fulvous, finely annulated 
with black, with generally a rather broad dorsal stripe of yellowish-red. The 
middle of the tail dorsally is of the same color as the middle of the back; 
the central reddish portion is bounded with black, the latter being fringed — 
with pale yellow. 
Var. richardsoni differs mainly from var. hudsonius in the general color 
of the upper surface being darker or more rufous, with the dorsal stripe 
