286 Mammals of Eastern Asia 
6. Medium- to small-sized Rats, in which the bases of the 
ventral hairs are gray, no matter what the color of their 
tips: 
n. eha group 
size small; fur very long 
and soft 
o. concolor group 
size small ; dull colored 
p. whiteheadi group 
size small; fur strongly 
spinous 
q. rattus group ( other than 
jalorensis, alexandrinus, 
and rattus) size medium ; highly vari- 
able with many races 
r. norvegicus group size larger (hind foot 1% 
inches), tail shorter than 
body. 
1. The largest of the Asiatic Rats, those with the length of the 
hind foot from 1% to 2% inches, include three of the species 
groups : edwardsi-sabanus , mulleri, and bower si. 
a. Edwards' Rats, Rattus edwardsi and relatives, include 
two easily recognized types : true R. edwardsi, gray or brown- 
ish gray above, white beneath, found only north of the Malay 
Peninsula, chiefly in the mountains, and R. sabanus and allies, 
colored strongly reddish brown on the back and occurring in the 
Malay area and out onto the Sunda Islands. A relative, R. pal- 
marum, lives on the Nicobar Islands. All have strong feet and 
claws and are good climbers. The nipple count is 8. 
The gray section of this group occurs in Assam, the Hima- 
layas, northern Burma, Yunnan, Laos, Annam, Tonkin, Szech- 
wan, and eastward along the hills of south China to Fukien. 
The length of the head and body is from 10 to 11 inches, tail 
12 inches, hind foot 2 to 2*4 inches. The typical race of 
edwardsi is from Fukien. The reddish section is composed of a 
large number of slightly differentiated forms, some of which are 
