MUS. 103 
white. Palms and soles naked, the former with five, the latter 
with six pads, the last hind pad elongate. Pollex with a short 
broad nail, all the other digits with claws: fifth digit on each 
foot without claw, reaching just to the base of the fourth. Tail 
about the length of the body without the head, slender, scaly, 
the scales rather irregularly disposed, very small, averaging about 
twenty to twenty-two to the centimetre, the whole tail very 
thinly covered with fine white hairs; its substance pale flesh 
color above and below. Palate-ridges as in Hydromys, i.e. three 
predental, the third notched in the centre, three interrupted inter- 
dental ridges, and one uninterrupted posterior ridge. Mamme 
0-2=4. Upper incisors long, less curved than in Mus, their 
front surfaces smooth, ungrooved, and orange in color: lower 
incisors very long, their front surfaces white. 
Habitat.—Port Mackay, Queensland. 
Dimensions.— 2 ad. Head and body about four and a half 
inches ; tail about three and a half inches. 
References.—Thomas, Proc. Zool. Soc. 1889, p. 247, pl. xxix. 
ff. 1—4 (skull), 5 (palate-ridges), 6 (anterior zygoma-root), 8 (ear), 
9 (right hind foot), and 10 —12 (left upper and lower molars). 
Subfamily [1.—Muvrina. 
Rats and Mice. 
Molars tuberculate, at least in youth. Cheek-pouches absent. 
Tail scaly, more or less naked. 
This sub-family contains about two hundred and fifty species 
belonging to eighteen well defined genera. 
Genus ITI.—MUS, Linneus (1766). 
Incisors narrow, not grooved: molars small, with three series 
of cusps across each tooth. Incisive foramina long. Coronoid 
process of lower jaw well developed. yes and ears large. Fur 
soft, sometimes mixed with spines. Pollex with a short nail 
instead of a claw. No cheek-pouches. Tail long, nearly naked, 
with rings of overlapping scales. 
Distribution.—Eastern Hemisphere, except Madagascar. 
Dentition.—I. 7, M. 2 = 16. 
Mamme.—Varying from six to twenty. 
Habits.—Terrestrial or semiaquatic ; fossorial ; normally grani- 
vorous, but under pressure of hunger, or when a semidomesticated 
existence has been taken up—such, for instance, as in the case of 
the House Mouse, Mus musculus, and the Brown Rat, Mus 
decumanus—omnivorous. 
