A FOURTH COLLECTION OF SIAMESE MAMMALS. 61 
2092/CBK.] Obtained by Messrs. Williamson and Smith’s collectors 
on 11 April 1916. 
Some of the lesser known spiny rats, with upper parts varying 
between tawny and clay colour and with sharply margined white under 
parts, are not easy to identify without reliably determined material to 
compare them with and therefore—though this specimen appeared to 
be Rattus lepidus, known hitherto from one adult only—-I sent it to 
Mr. Gerrit S. Miller, in whose charge the type is, with a request for 
his opinion; at the same time drawing attention to the size of the 
ears. Mr. Miller has very kindly replied as follows :— 
‘“‘T have compared the specimen with the type of Rattus lepidus 
and find that the two are virtually identical in all important charac- 
ters. All the differences, except perhaps that in length of ear, are 
such as might be expected to be shown by individuals of one species 
from one locality. Dr. M. W. Lyon looked at the specimens with me 
and is of the same opinion. 
“The differences are :—(a) ear ; yours measures now a little over 
21 mm., while ours are about L7.5, but the treatment of the two speci- 
mens was so different (the ears of yours having been spread out while 
drying while those of ours were allowed to shrink) that without more 
‘material I should not lay stress on these 3 or 4 mm; (b) fur; yours is 
less spiny (might be described as having spines mixed with the hairs, 
while ours has hairs mixed with the spines); (¢) colour; underparts 
just perceptibly more yellow, the differences more noticeable on the 
throat than elsewhere ; sides and upper parts identical except that in 
the type of lepidus the more abundant spines give a “ horny” cast ; 
(d) braincase and ante-orbital plate, a hair’s-breadth narrower in your 
specimen ; (e) bullae of your specimen slightly more inflated so that 
the beak is less prominent. There are no others that I can detect”. 
The present specimen has the following appearance :—upper- 
parts ochraceous tawny darkened on the back by the tips of the 
spines and rather greyish on the sides and limbs through exposure of 
the base of the fur; cheeks buffy. Below cream colour throughout. 
Hands and feet white, the latter separated from the creamy part of the 
hind leg by a hair-brown area above the ankle. Tail dark above and 
white below, the hair in agreement except at the tip where it is pale 
VOR? This NO 11918: 
