This species slightly exceeds the harvest mouse (_Mus messorius_) in
size, its ears are considerably larger in proportion, and the tail is
shorter. Compared with the common mouse (_Mus Musculus_) it is smaller,
the tail is more slender, and shorter, and the feet are likewise more
slender and proportionately much smaller; the ears are more distinctly
clothed with hairs.
The principal points of distinction between this and the two preceding
species are pointed out in the account of _M. elegans_.
Upon comparing the skull of _M. gracilipes_ (Pl. 34, fig. 4. _a_.) with
that of _Mus Musculus_, the most striking differences consist in its
shorter and broader form, the upper surface being more arched, the
interparietal bone has a relatively smaller antero-posterior diameter,
the occipital region is more convex, and continued more gently and
gradually into the upper region of the skull. The zygomatic arch, which
is unusually slender, is more dilated (especially on the anterior part)
thus giving a squareness to the general form. The nasal bones are not so
much attenuated posteriorly. The length of the skull is 8⅞ lines, the
greatest width is 5⅛ lines, and the distance between the outer side of
the incisors and the front molar is 2¾ lines.
The dentition is figured in Plate 34, figs. 4. _b_ and 4. _c_.
“This specimen was given me by Mr. Bynoe, the surgeon of the Beagle, who
caught it amongst some long dry grass.”—D.
MUS FLAVESCENS.
PLATE XIII.
Mus flavescens, _Waterh._, Proceedings of the Zoological Society of
London, for February 1837, p. 19.
_M. suprà colore cinnamomeo, lateribus capitis, corporisque, æquè ac
pectore, auratis; gulâ abdomineque flavescenti-albis: pedibus
sordidè albis: auribus mediocribus rotundatis, pilis flavis obsitis:
caudâ, corpore, capiteque longiore, suprà fuscâ, subtùs sordidè
albá: tarsis longis._
DESCRIPTION.—Fur long and moderately soft; general colour of the upper
parts bright brownish yellow; on the sides of the head and body
bright yellow; towards the rump of a deeper hue, and inclining to
orange; under parts pale yellow, or yellow-white; chest yellow.
The fur both of the upper and under parts of the body deep
plumbeous at the base. Feet flesh-colour, covered above with white
hairs: tarsi long, naked beneath. Ears small, tolerably well
clothed with hairs; those on the inner side yellow, but many of
them blackish at the base; on the outer side, the hairs are
blackish on the fore part and yellow on the hinder part. The hairs
of the ordinary fur of the back are of a deep rich yellow colour
at the tip, and the longer hairs are blackish. The tail is long,
deep brown above and whitish beneath, the hairs of the moustaches
are rather short and slender, and of a brownish colour. Thumb nail
small and rounded.
In. Lines.
Length from nose to root of tail 3 9
of tail 4 1½
from nose to ear 1 0
of tarsus 1 0½
of ear 0 4½