82 MR. KLOSS ON WHITE-TOOTHED RATS FROM SIAM. 
Pelage composed of soft under fur and longer stiffer hairs, or 
spines not visibly flattened. 
Colour above glossy Natal brown slightly grizzled by the buffy 
tips of the under-fur ; sides of head, neck, body and the limbs paler, 
duller and rather more grizzled: base of under fur neutral grey, of the 
longer stiffer hairs whitish. Below white throughout. Foredigits 
whitish, metapodials brown. Feet white, the median line of the meta- 
podials clearly defined brown; anhles brown, Tail dark above, pale 
beneath where the hair clothing it is pale: the terminal 15 mm. pale 
all round. 
Skull with broader ante-orbital foramina than in R. 6. lact- 
wenter, the front edge of the plate slightly convex and overhanging the 
base ; palatal foramina longer and pointed posteriorly, bullae relatively 
rather smaller. 
Measurements of Siamese White-toothed Rats in millimetres. 
beer se OF 
Bis Es $ 
Ss 38 iS 
—e Pies tr 
RS 8 Re 
Head and body ose tee eee 180 235 215 
Tail “ee eee eee coef 152 255 242 
Hindfoot s. u. vee vee vee 37.5 50.5 46 
Ear s'se Jas ose wee 24 28.5 26 
Skull :— 
greatest length ... eee eee 40.3 53 45.5 
condylo-basilar length ... eee 38 * 47.4 42 
palatilar length ... see eee 20 25.2 22.2 
diastema oes ove ose 13 16.5 14 
upper molar row (alveoli) eee 7.2 9.1 8.8 
combined palatal foramina ons] 4 Oe 8.3 x 3.2 8.9 x3 
m3—m3 (alveoli) ... eee vee] 3.4 5 4.2 
nasals és née ooo 14.7% 4.6) 226.8 | 18.3x6.1 
interorbital breadth bay ons 6.3 7.7 6.9 
brain case breadth eee eee 17 19.7 18.2 
zygomatic breadth eee sei 21.6 26.1 23.4 
nn 
* Approximate 
JOURN. NAT. HIST. SOC, STAM. 
