MURIDE 473 
in the Pleistocene of the Altai, while an extinct one has been 
described from the Pliocene of North China. 
Subfamily Deomyinse. — Represented only by the under- 
mentioned genus, in which the bituberculate anterior and tricusp- 
idate middle ridge of the first upper molar presents a condition 
intermediate between that obtaining in the ('ricetine and that of 
the Murine. 
Deomys.A—Externally as in aus. Pollex with a narrow nail ; 
hind feet elongate. Infraorbital vacuity of skull triangular, not 
narrowed below. Upper incisors with a pair of minute grooves. 
First upper molar with seven distinct tubercles, of which three are 
placed on the middle ridge, and two on each of the others. One 
species, J. ferrugineus, from the Lower Congo, an animal about the 
size of the Common Mouse. 
Subfamily Murine. — Molars rooted and tuberculated ; those 
of the upper jaw with three longitudinal rows of tubercles (Fig. 
206, 1). 
This group includes the true Rats and Mice, and may be 
regarded as more 
specialised than 
the Cricetina. 
All the members 
of the group 
closely resemble 
one another, and 
are light and 
active, with large 
ears, bright eyes, 
and long and 
sealy tails. Their 
coloration, in 
conformity with 
the fossorial and 
nocturnal habits 
of most of the 
forms, is sombre, 
and their move- 
ments are re- 
markably agile 
and graceful. 
* . Fra, 211.—The Australian Brown-footed Rat (Mus ficsei pes). 
Mus.2—Incisors ‘After: Gould. 
narrow, without 
grooves. Structure of molars as in Fig. 206, 4 (p. 463). Incisive 
foramina of skull long ; coronoid process of mandible well developed. 
1 Q. Thomas, Proe. Zool. Soc. 1888, p. 130. 
2 Linn, Syst. Vat, 12th ed. vol. i, p. 79 (1766). 
