"This small rat is found in out-houses in the cinnamon gardens at Colombo. I have no reason to think it to be the young of the former species (M. decumanus); the teeth were well developed; the darker colour and long tail will easily distinguish the species from other Colombo rats" (Kellaart). The character of the molar teeth is all that can be depended on in the foregoing description, and this may require further investigation. The young of rats and mice are always darker than the adults, and the tail is longer in proportion.
The following are doubtful species:—
[NO. 348. MUS PLURIMAMMIS.]
Jerdon's No. 177.
This, which Blyth considered a good species, is, I am informed, referable with M. Taraiyensis and M. Morungensis to Gray's Nesokia Bengalensis. The type and drawing of it are in the British Museum.
of Hodgson, described in Horsfield's Catalogue as pure dark brown above, with a very slight cast of rufescent in a certain aspect; underneath from the chin to the vent, with interior of thighs, yellowish-white; ears nearly an inch long; head proportionately long ('Ann. and Mag. Nat. Hist.' new series, iii. p. 203). This, with Blyth's M. nemoralis, seems identical with M. brunneus.
Mus arboreus of Horsfield's Catalogue is Mus rufescens. It remains to be seen whether there is sufficient difference between M. rufescens and M. niveiventer to warrant the separation of the latter as a distinct species.
The following species lead on to the mice—beginning with the long-tailed arboreal species, Vandeleuria of Gray, which connect the arboreal rats with the house mice.
The characteristics of Vandeleuria are: upper incisors triangular, grooved in front; ears hairy; fur soft, with long bristles interspersed; long tail, sparsely haired; hind feet very long, slender; soles bald beneath; toes ·45 long, slender, compressed, the pads much more strongly developed than in ground mice; the inner and outer toes with a small flattened nail.
[NO. 350. MUS OLERACEUS.]
The Long-tailed Tree Mouse (Jerdon's No. 184).