HORN EXPEDITION—MURID.E. 
397 
Skull (con tin ued). 
Var. 
brachyotw. 
B. J 
F. J 
Nasals, length - 
- 
13-8 
12-8 
Nasals, greatest breadth 
- 
3-8 
3-7 
Interorbital breadth 
- 
5-3 
5-1 
Interparietal length 
- 
5*5 
5*8 
Interparietal breadth 
- 
9-2 
90 
Brain-case, breadth 
- 
15-8 
lo‘6 
Anterior zygoma root 
- 
3-5 
31 
Diastema 
- 
9-3 
8-7 
Palate, length 
- 
190 
17-8 
Anterior palatina foramina 
- 
7 0 
6(> 
Upper molars, length 
- 
(j-b 
o-o 
Lower molars, length 
- 
6-8 
07 
Condyle to incisor tix^ 
- 
240 
22-3 
Coronoid tip to angle 
- 
9-4 
8-2 
Habitat .—Alice Springs and (variety) Illaiuurta, Central Australia. 
Of seven examples two, marked F and G, ditier from the others in being 
slightly smaller, in having the ears proportionately smaller, reaching only to the 
posterior margin of the eye, and in the tail being shorter than the head and body. 
The tail is similar to the typical examples, but is less incrassated, and is destitute 
of yellow hairs, being black above and white below throughout; basally the hairs 
are scanty and do not hide the scales, but are longer distally. The scales are also 
much smaller, averaging seventeen to the centimetre. It may be that these several 
points are of specific value, but as the two skulls examined do not differ materially, 
the writer, for the present, prefers to regard this form as a well-marked variety, 
which may be known as var. brachyotis, characterised as above. One of the two 
specimens was collected by Mr. E. 0. Cowle at Illamurta, James’ Range. The 
other was in the parcel received from Mr. J. Field at Alice Springs. 
The remarkable thickening of the tail of this species above referred to was 
conjectured to be due to a layer of fat stored for the purpose of food supply. On 
