SCIURIDAZ—SCIURUS AURBIGASTER. Til 
and the rufous tint of the lower parts from reddish-orange to strong reddish- 
brown or fiery-chestnut. One specimen (No. 7205) is wholly black, very 
minutely sprinkled on the sides with reddish-gray; the hairs of the tail 
wholly black to the base. Another (No. 8923) is dusky, with the middle of 
the back, the feet, most of the head, the ears, and the tail black; sides and 
most of the dorsal surface varied with pale reddish-brown; lower parts mixed 
black and rufous. Another (No. 8489) is blackish above, varied with white, 
with a faint rufous tinge across the shoulders; whole top of the head, feet, 
and exterior of hind limbs black, the former slightly varied with whitish ; 
cheeks and chin gray; whole lower surface intense orange-red; tail below 
wholly black, except a narrow mesial line of mixed rufous and black toward 
the base; upper surface of tail mixed white and black. In No. 72038, the 
red of the lower surface extends high up on the sides, meeting over the 
shoulders, and more or less tinges the whole dorsal surface, except the head, 
which is clear blackish-gray. Tail centrally more or less red below. In No. 
7847, the lower surface is fiery-orange, which color impinges upon the dorsal 
surface at the shoulders, not, however, extending quite to the median line. 
The rest of the dorsal surface is clear blackish-gray. Tail below broadly 
centred with rufous. In No. 7848, the colors have the same distribution, 
but the gray of the upper parts is lighter, the white predominating over the 
black. The middle of the tail below is deep reddish-brown throughout, bor- 
dered by a broad band of black, and edged and tipped with white. In No. 
3262, the posterior half of the back is nearly white. In No. 6352, while the 
distribution of the color is the same as in No. 7848, the color below is dark 
red, which prevails over the shoulders with almost the same intensity as below. 
Except where the tints are obscured by melanism, the pattern of the 
coloration remains quite constant, the variation being mainly in reference to 
the varying proportions of black and white of the upper parts, in the intensity 
of the red of the lower surface, and in the extent of its encroachment upon 
the dorsal surface. 
The Sciurus aureegaster of F. Cuvier, as shown by the description and 
figure, especially the latter, refers unquestionably to this species. The S. 
aureogaster of Gervais, however, is an entirely different animal, namely, the 
Macroxus leucops of Gray, as is shown in the discussion of the synonymy of 
that species. IF. Cuvier’s S. eucogaster, the description of which I have not 
seen, is referred by Baird and others to Cuvier’s S. aureogaster. 
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