MURIDAE RECORDED FROM VICTORIA 
65 
Description of an Average Victorian Specimen. 
General colour olive-tawny, suffused on the neck and forepart of the body 
with an orange hue. Dorsal surface grizzled with black hairs which are not 
sufficiently numerous to hide the yellow fur. Sides of body and outer sides 
of limbs lighter. Ventral surface buffy-yellow. Head a little darker than 
body, cheeks with an orange-buffy patch below the eye. Mysticial vibrissae 
long and numerous; shorter anterior hairs white, longer posterior hairs black. 
Ears short and dark brown. Basal inch of tail clothed with hair of body, 
remainder with stiff adpressed hair which completely hides scales; black for 
a varying distance of somewhat more than half its length, then with a con- 
spicuous white tip. Manus and pes well covered with silky adpressed hair. 
Manus with a black patch on the wrist; phalanges and nails white. Pes 
uniformly dark brown. 
Skull . — Heavily built, rounded, and without any marked ridges. In profile 
the upper border is remarkably straight. Bullae small. 
Teeth . — Incisors long and strong. Two molars only, the anterior nearly 
three times as long as the posterior and divided into three laminae in the upper 
and two in the lower jaw. 
General Dimensions . — Head and body, 320 mm. ; tail, 317 mm. ; hind foot, 
73 mm. ; ear, 19 mm. 
Dimensions of Skull . — Greatest length, 55 mm.; basal length, 50- 5 mm.; 
greatest breadth, 27 mm.; nasals, 17 5 X 6-5 mm.; interorbital breadth, 
7-5 mm.; palate length, 29 mm.; breadth inside M 2 , 7 5 mm.; breadth out- 
side M 2 , 11 mm.; diastema, 15 mm.; palatal foramina, 5 mm.; upper molar 
length, 8-5 mm. 
The above description applies to about 65 per cent, of the 
rats examined, but tlie perfect gradation from very deep 
brown to grey does not allow of any sharp division. An 
increase, or otherwise, of black hairs causes variation in the 
depth of dorsal colour and also in the distinctness of the line 
of demarcation between the dorsal and ventral surfaces ; this 
line may be well marked or absent. Of the remaining skins 
about 10 per cent, are of varying degrees of greyness to a cold 
grey above and whitish below, and 25 per cent, are darker to 
a deep brown above and orange below. Specimens almost 
black above and reddish-orange below are not common, and 
seldom exceed more than one in each batch of 400 to 600 skins. 
Though specimens can be found to match most of the geo- 
graphical races mentioned above, there is obviously little use 
in so classifying them ; great variation in colour occurs in a 
single and quite restricted locality, and the species must be 
considered generally, rather than racially, variable in colour. 
Interbreeding between the various colour forms takes place. 
The suggestion is ventured that at least some of the subspecific 
forms mentioned above are founded on insufficient material 
and cannot be accepted as valid. 
