RHIZOMYS. \ 329 



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

 of Bangkok and referred by A. M.-Edwards^ to H. hadius appears to be this 

 species. 



*E,HizoMTS BADius, Hodgson. Plates XIY & XVI. 



Rhizomys laclius, Hodgson^ Cal. Journ. Nat. Hist. 1843, 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; Schinz, Syn. Mamm. 1845, vol. ii. p. 126; Jerdon, 



Mamm. Ind. 1867, p. 214. 

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



Soc. Bengal, 1863, p. 123. 



This species was first 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 colour 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 R. pruinosus, and the tail is Kttle more than 

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

 B. pruinosus, from which it is also easily distinguished by its rather brightly colom^ed 

 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 brilliant in the animals I 

 procured 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 even to slaty- 

 grey, washed mth 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 structm^e, such as in the length of the facial 

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

 nasals. In some skuUs, 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, wliilst 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 sweU 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 Mammif., p. 295. 



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