62 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
The molars of the upper jaw are figured in Plate 34, fig. 13, a, and those of 
the lower jaw, fig. 13, b. 
“ Caught in the interior plains of Patagonia in lat. 50°, near the banks of the 
Santa Cruz.” — D. 
23. MUS GRISEO-FLAVUS. 
Plate XXI. 
Mus griseo-flavus, Waterh ., Proceedings of the Zoological Society of London for February 1837, p. 28. 
M. supra griseus flavo-lavatus, ad latera Jlavus, subiiis albus ; pedibus albis ; auribus 
magnis et ferb nudis ; caudd caput corpusque ferb ce quant e, supra fusco-nigricante, 
subtus alba ; vellere longo , molli. 
Description. — Ears large ; tail rather shorter than the head and body taken 
together ; tarsi slender, and moderately long ; fur long and very soft ; general 
tint of the upper parts of head and body grayish, washed with brownish yel- 
low ; on the sides of the body a palish yellow tint prevails ; feet, chin, throat, 
and under parts of body pure white ; tail rather sparingly clothed with 
hairs, those on the apical portion rather long, and forming a slight pencil at 
the tip ; on the upper side and at the tip of the tail the hairs are brown, on 
the under side they are dirty white ; the ears are very sparingly clothed with 
minute brownish yellow hairs internally ; externally, on the fore part, the 
hairs are rather longer and of a brown colour ; the upper incisors are orange, 
and the lower incisors are yellow ; the hairs of the moustaches are long, and 
of a black colour ; the hairs of the back are deep gray at the base, brownish 
at the tip, and annulated with pale brownish yellow near the tip ; the longer 
hairs are brown ; the hairs of the belly are white externally, and gray at the 
base ; on the throat the hairs are white to the root. 
Length from nose to root of tail 
of tail 
from nose to ear 
In. Lines. 
. 6 8 
. 5 6 
• 1 
Length of tarsus (claws included) 
of ear 
In. Lines. 
1 2J 
. 0 8 
Habitat, Northern Patagonia (. August .) 
The molars of the upper jaw are figured in Plate 34, fig. 15, a, and those of 
the lower jaw, fig. 15, b. 
“ Inhabits the dry gravelly plain, bordering the Rio Negro.” — D. 
