Dr. Gray, when he described this species, was uncertain whether it inhabited
India or Cochin China, hut in the India Museum, London, there is a bamboo-rat bearing
this name of 22. mmor; Gray, and which was brought from Siam by Dr. Einlay-
son, a member of Crawford’s mission to Cochin China and Siam. There is also in the
British Museum a specimen resembling this Siam rat-mole, and which is stated to have
been procured by M. Mouhot in Cambodja. Dr. Horsfield doubtfully includes the
thur of the Siamese, which Dr. Gray had considered to be 22. badms, as a synonym
of 22. mmor, but he expresses no dubiety regarding the specific identity of his
Siam animal with that of JR. mmor, Gray. Dr. Gray, in his communication to the
Annals and Magazine of Natural History in 1842, mentions that only some of the
new animals therein described were in the National Collection, and it may therefore
be, as he suggested, that Cochin China was the habitat of 22. minor, that the specimen
now in the India Museum from Siam is the type of the species; and that Dr. Gray
erroneously named Cochin China instead of Siam as the locality from whence
it was obtained, as Crawford’s embassy was known as a mission to Cochin China.
This view of the question is strengthened by the circumstance that the India
Museum specimen exactly agrees with Dr. Gray’s measurements of his type and
with his description.
, Both specimens may be described as dark sooty-brown, slightly tinged with
deep umbra: which is most distinct on the sides of the head and neck and in
reflected lights, but is least marked in the Cambodja specimen. The under parts
are like the upper, only the brown tint is almost absent. The whiskers are
black, and the tail has been very sparsely haired,. as in 22. castcmeus and 22.
bcidius.
Dr. Gray’s type measured 6'50 inches from the muzzle to the root of the tail,
and the tail was 175 inches in length, which are the measurements of the India
Museum specimen. The example in the British Museum from Cambodja is 7'30
inches in the former, and 2'20 in the latter of these two measurements. The skull
of the larger specimen is considerably smaller than the skull of adult examples of
22. badms, so that it is probable that the species does not attain to the size of the
latter. I t is also closely allied to 22. badvus, as is evidenced by the strong similarity
of the skull to the skull of that species, but the colour of the fur is pronouncedly
different. The skull in the British Museum removed from the Cambodja specimen
(Plate XVI, figs. 7—9) differs from the skull of 22. badms in its smaller breadth across
the zygomatic arch and in the expansion and flattening of the frontal region. The
palatal surface across the premaxillary foramina is broader than in 22. badms, and
there is a rather prominent ridge running along its outer wall to the outside of the
base of the front molar. The palatal surface is also broader than in 22. badms, and
the alveolar border is much longer than in that species, and the muzzle also is somewhat
longer and the infraorbital foramen larger. The palatal border of the posterior
nares is much more contracted than in the other species, the ends of the palatines
being divergent at a very, acute angle, and it is placed more anteriorly than in the
other species, being opposite to the middle of the last molar.
The small bamboo-rat obtained by M. Boucourt from Sarabari to the north
of Bangkok and referred by A. M.-Edwards1 to 22. badius appears to be this
species.
* R h iz o m y s b a d iu s , Hodgson. Plates XIV & XVT.
Rhizomys badius, Hodgson, Cal. Joum. Nat. Hist. 1842, vol. ii. pp. 60, 410 ; Gray, List Mamm.
B. M. 1843, p. 150; Gray, Cat. Hodgson's Coll. 1845, p. 24; Blyth, Joum. 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, Joum. As. Soc. Bengal, 1848, 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. I t 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.
I t does not attain to the size of JR. prwmosus, and the tail is little more than
one-third thé length of the body, and has a more abruptly truncated end than
22. prumosus, from which it is also easily distinguished by its rather brightly coloured
chestnut fur. I t 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 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 premaxillaries are prolonged
behind the nasals and touch the ridge proceeding from the external angle of
the frontal, whilst 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 soipe 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 all but lost in others.
Recherches des Mammif., p. 295.
2