CHARACTER.—"Lower incisors compressed; no premolars; molars rooted or rootless, tuberculate or with angular enamel folds; frontals contracted; infra-orbital opening in typical forms high, perpendicular, wide above and narrowed below, with the lower root of the maxillary zygomatic process more or less flattened into a perpendicular plate; very rarely the opening is either large and oval, or small and sub-triangular. Malar short and slender, generally reduced to a splint between the maxillary and squamosal processes; external characters very variable; pollex rudimentary, but often with a small nail; tail generally sub-naked and scaly, rarely densely haired."—Alston, 'P. Z. S.' 1876.
This family is divided into about ten sub-families, of which the Indian ones are as follows: Platacanthyominæ; Gerbillinæ; Phlæomyinæ; Murinæ; Arvicolinæ; Cricetinæ.
The other four are Sminthinæ, Hydromyinæ, Dendromyinæ, and Siphneinæ, none of which are found within our limits.
CHARACTER.—Molars 3/3, divided into transverse laminæ; infra-orbital opening as in typical Muridæ; incisive foramina and auditory bullæ small; form myoxine (or dormouse-like); fur mixed with flat spines; tail densely hairy. The general resemblance of this animal to the dormouse (Myoxus) is striking, to which its hairy tail and its habits conduce, but on closer examination its small eyes, thin ears, short thumb of the fore-foot bring it into the murine family. The genus was first noted and named by Blyth, who seemed inclined to class it as a dormouse, but this has not been upheld for the reasons given above, and also that Platacanthomys has the normal murine number of molars, viz.: 3—3/3—3, whereas Myoxus has an additional premolar above and below. These points were first brought to notice by Prof. Peters of Berlin (see 'P. Z. S.' 1865, p. 397). There is a coloured plate of the animal in the same volume, but it is not so well executed as most of the illustrations in the Society's works.
[NO. 316. PLATACANTHOMYS LASIURUS.]
The Long-tailed Spiny Mouse (Jerdon's No. 198).
HABITAT.—Southern India.
DESCRIPTION.—Light rufescent brown; the under fur paler, more rufous on the forehead and crown; whiskers black; under parts dull white; the hairs on the tail, which are arranged distichously, are darker than those of the body, infuscated except at the tip of the tail, where they are whitish; the muzzle is acute; ears moderate and naked; the fur above is mixed densely with sharp flat spines; the under coat is delicate and fine; the few spines on the lower parts are smaller and finer; the thumb is without a nail.
SIZE.—Head and body, 6 inches; tail, 3½, or five inches including the hair; planta, 1 inch.
This species was discovered by the Rev. Mr. Baker in the Western Ghâts of Malabar, and in Cochin and Travancore, at an elevation of about 3000 feet. He writes of it: "It lives in clefts in the rocks and hollow trees, and is said to hoard ears of grain and roots, seldom comes into the native huts, and in that particular neighbourhood the hillmen told me they are very numerous. I know they are to be found in the rocky mountains of Travancore, but I have never met with them on the plains." In another place he adds: "I have been spending the last three weeks in the Ghâts, and, amongst other things, had a great hunt for the new spiny dormice. They are most abundant, I find, in the elevated vales and ravines, living only in the magnificent old trees there, in which they hollow out little cavities, filling them with leaves and moss. The hill people call them the 'pepper-rat,' from their destroying large quantities of ripe pepper (Piper nigrum). Angely and jackfruit (Artocarpus ovalifolia and integrifolia) are much subject to their ravages. Large numbers of the shunda palm (Caryota) are found in these hills, and toddy is collected from them. These dormice eat through the covering of the pot as suspended, and enjoy themselves. Two were brought to me in the pots half drowned. I procured in one morning sixteen specimens. The method employed in obtaining them was to tie long bamboos (with thin little branches left on them to climb by) to the trees; and, when the hole was reached, the man cut the entrance large enough to admit his hand, and took out the nest with the animals rolled up in it, put the whole into a bag made of bark, and brought it down. They actually reached the bottom sometimes without being disturbed. It was very wet, cold weather, and they may have been somewhat torpid; but I started a large brown rat at the foot of one of these trees, which ran up the stem into a hole, and four dormice were out in a minute from it, apparently in terror of their large friend. There were no traces of hoarding in any of the holes, but the soft bark of the trees was a good deal gnawed in places. I had two of these dormice alive for some time, but, as they bit and gnawed at everything intended to keep them in durance, I was obliged to kill both. I noticed that when their tails were elevated, the hairs were perfectly erect like a bottle-brush" ('Proc. As. Soc. Beng.' 1859, p. 290).