52 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
In the collection there are three specimens of the present species ; in one 
of these the hairs of the upper part and sides of the body are annulated with 
yellowish white, instead of yellow ; hence the general hue of these parts is nearly 
gray. 
MusRenggeri is larger than Mus Musculus, and much stouter in its proportions ; 
the fur is shorter, much less dense, and less soft than in Mus brachiotis. 
“ It inhabits dry stony places, where only a few thickets grow.” — D. 
15. Mus OBSCURUS. 
Plate XV.— Fig. 2. 
Mus obscurus, Waterh., Proceedings of the Zoological Society of London for February 1837, p. 16. 
M. supra fusco-nigrescens, subtiis jiavescens ; pedibus obscuri fuscis ; unguibus longius- 
culis ; auribus mediocribus ; caudd corpore breviore, supra nigrescente , subtus sordidb 
alba ; vellere mediocri, molli. 
Description. — Head large; ears moderate; tail shorter than the body; fur rather 
long and glossy ; the general hue of that of the upper parts and sides of the 
head and body is blackish brown, and that of the under parts is dirty yel- 
lowish white. The hairs on the upper parts are of a deep lead colour at the 
base, black at the apex, and narrowly annulated with dark yellow near the 
apex ; those of the throat and belly are lead colour at the base and yellowish 
at the tip ; the chin is white : around the eye, and on the lower part of the 
cheeks a deep yellow tint prevails. The ears are well clothed with hairs both 
externally and internally, and these are for the most part of a deep brown 
colour, as are also the hairs which cover the feet. The tail is well clothed 
with hairs, those on the upper surface are black, and those on the under are 
dirty white. Both upper and lower incisors are yellow, but the lower are 
paler than the upper. 
In. Lines. In. Lines. 
Length from nose to root of tail . .53 Length of tarsus (claws included) . . 0 11| 
of tail 2 7 of ear 0 4 
from nose to ears . . .12^ 
Habitat, Maldonado, La Plata, ( June.) 
The present species, like the foregoing, is much stouter than the common 
