30 
FASCICULI MALATENSES 
50. Mus £^risei venter, sp. nov. 
(Plate II, fig-. 3 , and Plate IV, fig-. 5 ). 
A species of the Mus rattus group. Fur soft, short, and close, containing 
a few slender and scattered spines. 
General colour of upper parts very much as in the last species, but rather 
paler and more uniform in coloration throughout, being hardly, if at all, 
darker along the centre of the back. Under parts uniform dull grey, with a 
yellowish tinge caused by fulvous tips to some of the hairs. Feet, dark brown ; 
ears short, naked, and rounded. Tail rather longer than the head and body, 
of a uniform black throughout, covered with numerous short stiff black hairs. 
Skull. Similar to that of Mus jalorensis^ but longer and narrower. The 
nasals do not appear to taper quite as much, and the supraorbital ridges are 
more strongly marked and inclined outwards. The bullae are slightly larger, 
not converging anteriorly quite as much, and the incisive foramina are also 
rather narrower. 
Dimensions of type (measured in the flesh) : — Head and body, i6i mm. ; 
Tail, 212 mm. ; Hind foot, 35 mm. ; Ear, 19 mm. 
Skull. Greatest length, 42 mm. ; Basal length, 35 mm. ; Palatal length, 
20 mm. ; Diastema, 12 mm. ; Length of incisive foramina, 7 mm. ; Length 
of nasals, 1 5 mm. ; Combined breadth of nasals ; Anteriorly, 4 mm. ; 
Posteriorly, 2 mm. ; Zygomatic breadth, 19 mm. ; Interorbital breadth, 
6 mm. ; Breadth of brain case at roots of zygomata, 15 mm. ; Length of 
molar series, 7 mm. 
Habitat. Bidor, South Perak. 
Fype. Adult female, collected on the 3rd February, 1902. Original 
number, 215. 
The size of the hind foot and comparative shortness of the ear form two 
features by which this species may be easily recognized. The uniform dull 
coloration and grey under parts enable it to be distinguished at a glance from 
Mus jalorensis. The tail in the type appears somewhat longer than that in the 
remainder of the series. 
Four specimens, 2 $ and 2 9 , were brought back, all from the same 
locality. The average measurements of the four are : — Head and body, 
155 mm. ; Tail, 177 mm. ; Hind foot, 34 mm. 
‘A house rat ; very abundant in the Bidor rest-house.’ 
51. Mus annandalei, sp. nov. 
(Plate IV, fig. i). 
A medium-sized rat, allied to Mus neglectus^ Jent. Fur soft and moder- 
ately long ; entirely destitute of spines. 
