RHIZOMYS. 329 



The small bamboo-rat obtained by M. Boucourt from Sarabari to the north 

 of Bangkok and referred by A. M.-Edwards' to B. badms appears to be this 

 Bpecies. 



*Rhizomts badius, Hodgson. Plates XIV & XVI. 



Mizomys ladius, Hodgson, Cal. Journ. Nat. Hist. 1842, vol. ii. pp. 60, 410; Gray, List Mamm. 

 B. M. ]843, p. 150; Gray, Cat. Hodgson's Coll. 1845, p. 24; Blyth, Journ. As'. Soc. Bengal, 

 1843, vol. xii. p. 925; Blyth, Cat. Mamm. As. Soc. Mus. Cal. 1863, p. 122; Horsfield, Cat' 

 Mamm. E. Ind. Co.'s Mus. 1851, p. 165; Sehinz, Syn. Mamm. 1845, vol. ii. p. 126 • Jerdon 

 Mamm. Ind. 1867, p. 214. 



Rhizomijs castaueus, Blyth, Journ. As. Soc. Bengal, 1843, vol. xii. p. 1007; Cat. Mamm. Mus. As. 

 Soc. Bengal, 1863, p. 123. 



This species was iirst discovered by Hodgson in Nepal and afterwards obtained 

 by Blyth in Arracan. It would appear as if the Himalayan examples were generally 

 somewhat duller in coloiu' than those from Arracan and Burma, and this difference 

 led Blyth to regard the eastern race as a distinct species, but there are no facts to 

 support such a conclusion. 



It does not attain to the size of B. pruinosus, and the tail is Httle more than 

 one-third the length of the body, and has a more abruptly truncated end than 

 B. pruinosus, from which it is also easUy distinguished by its rather brightly coloured 

 chestnut fur. It is also separated from that species by the absence of the tubercles 

 on the feet. 



The fur is fine, and uniformly grey in two-thirds of its extent, the apical third 

 being some shade of chestnut which is especially brUliant in the animals I 

 procm-ed in the Kakhyen hills, most intense on the head, and dullest on the rump. 

 The fur of the under parts, in these eastern examples of the species, is paler and 

 more reddish than chestnut, whereas in some Nepal animals it inclines eyen to slaty- 

 grey, washed with reddish. The area immediately around the muzzle and the chin 

 is pale brownish with a tinge of greyish, and the teeth are brilliant reddish, the 

 nose, ears, feet, and tail being pale flesh-coloured. 



Skulls of this species (Plate XVI, figs. 4 — 6) manifest considerable variation in 

 some of the minor details of their structure, such as in the length of the facial 

 portion of the premaxillaries and the extent of the backward prolongation of the 

 nasals. In some skulls, the posterior ends of the latter bones are rounded, while in 

 others they are rather abruptly truncated. Occasionally the premaxiUaries are pro- 

 longed behind the nasals and touch the ridge proceeding from the external angle of 

 the frontal, wlulst in other skulls they do not extend so far back. The external 

 angles of the frontals are also much less prominent and less nodular in some than 

 in others in which they swell more into the area anterior to the frontal contraction. 

 In some skulls also there is a somewhat flattened area between the superior orbital 

 angles, which is aU but lost in others. 



' Eecherches des Mammlf., p. 295. 



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