OCR Text |
Show 1890.] MR. W. L. SCLATER ON SOME INDIAN MURID.E. 533 quarter being chestnut. The body beneath, including the chin, throat, and sides of tho muzzle, is white without any slate-coloured base; the two colours are abruptly separated from one another. The sides of the snout from which the whiskers spring are considerably swollen ; the ears are large, rounded, and covered with very scanty short single hairs, so that unless looked at carefully they appear to be naked : when bent forward they easily reach the eye. The tail is very long, much longer than the head and body ; the basal portion is comparatively bare; the distal portion is covered with gradually increasing quantities of hair, those at the tip of the tail reaching a length sometimes of -20 of an inch ; the tail is quite uniformly coloured, it is not lighter above than below. On the fore feet there are four well-developed toes, all clawed ; the first digit is represented by a mere stump springing from the inner proximal sole-pad and is provided with a flat nail; the toes are all much swollen distally by the great development of the toe-pads, which is very well shown in Peters's plate (I. c.) ; in the hind foot the first digit is very stumpy, and only reaches to the level of the base of the division between the second and third toes, it is provided with a flat nail; the toe-pads are swollen in the same way as are those of the fore feet; the sole-pads are large and well-developed, and the proximal inner one is oblong and rat-like. In the only specimen in which the mammae could be made out, they were four in number, and all situated abdominally on either side on a level with the femur; no traces of pectoral or inguinal mammas were to be found ; whether this is a constant character or not must be decided by the examination of more specimens. The skull of Chiropodomys (Plate X L V . fig. 6) resembles that of Vandeleuria more than that of any other Indian Mouse ; in general appearance it is very wide and short, its breadth being greater than that of any other Indian Mouse or Rat. The nasal bones are so short that the nasal processes of the premaxillae reach back to a considerable distance behind their posterior ends ; this is also the case in Vandeleuria, but it is not nearly so marked a feature. The interparietal is crescent-shaped, with an anterior median projection between the two parietals. The antorbital plate is perfectly straight and perpendicular, as in Vandeleuria and Mus erythrotis; below the anterior palatine foramina are very short, shorter than in any other Indian Rat, they are also rather broad, and present a kidney-shapped appearance. The posterior nasal opening is very wide, almost as wide as the hard palate ; it is equal to more than half the length of the anterior palatine foramen, while in Vandeleuria its width is very much less than half the length of the anterior palatine foramen. The dentition of this species (Plate X L V . fig. 11) appears to be somewhat intermediate between that of Vandeleuria and typical Mus. The anterior upper molar in Mus consists of three central, three external, and two internal cusps, the posterior internal cusps being absent; in Vandeleuria there are eight cusps as in Mus, but PROC. ZOOL. Soc-1890, No. XXXVI. 3G |