Descriptions of East Asiatic Mammals 285 
1. Very large forms, with the length of foot 1% to 2*4 
inches and white underparts: 
a. edwardsi-sabanus group fur brown or gray 
b. millleri group fur gray 
c. bower si group fur gray 
2. Medium-sized form, with the length of foot 1% to 1% 
inches, black or gray-black above and below : 
d. rattus rattus, the Com- fur black, above and be- 
mon Black Rat. neath. 
3. Medium- to small-sized gray or brownish gray forms hav- 
ing the ventral hairs white to the roots : 
e. rattus alexandrinus, the 
Roof Rat or Alexan- 
drine Rat 
f. 
andersoni group 
fur soft 
g- 
canus group 
fur soft 
h. 
berdmorei group 
size medium, hair coarse; 
incisor teeth whitish 
i. 
confucianus group 
J- 
rattus jalorensis, the 
Malaysian Field Rat 
4. Medium-sized forms with reddish upperparts and white 
underparts : 
k. rajah group fur spinous in most species, 
at least seasonally 
5. Small-sized Rats, the length df the foot about 1 inch, with 
reddish pelage and white underparts : 
1. cremoriventer group fur spinous in most species, 
tip of tail tufted, 
m. fulvescens-huang group tip of tail not tufted 
