146 



upper molar-row, 6.7 (7) ; length of lower inolar-row, G.5 (7) ; length 

 of palatal foramina, 6.75 (6.5) ; combined hreadth of foramina, 4.75 

 (3.75) ; breadth of palate V>etween anterior molars, 5 (5) ; medium 

 length of nasals, 18.5 (17) ; interorbital breadth, 7.75 (7) ; cranial 

 breadth, 17 (17.5) ; zygomatic breadth, 20 (20). 



Specimens examined. — Eight from the type locality. 



Remarks. — Thi.s insular form is strikingly charactei'ised by the 

 great reduction that has taken place in the crowns of the molars. 

 The change, however, does not yet appear to have affected the roots of 

 the teeth, although the smaller size of the molar-row, combined with 

 the broader foramina and inter-pterygoid space, causes the palate to 

 appear wider: the mandible also, though proportionately less robust 

 and powerful, and with the various processes somewhat atrophied, is 

 not reduced in length. Compensation for these diminutions has been 

 given in the form of a larger and hea"vaer rostrum. 



MUS VILLOSUS. sp. nov. 



Type. — Adult male(skin and skull), No. 1348/08, Selangor Museum. 

 Collected in the Botanical G-ardens, Singapore, 12th July, 1908, by 

 C. Boden Kloss. 



Characters. — A large member of the Mnelleri group, externally 

 somewhat like Mus validits, Miller, but smaller, duller and less shaggy, 

 and with colour of under-parts distinctly margined on sides. Fur long 

 and moderately soft, devoid of spines, but thickly sprinkled with 

 long coarse bristles. The skull like that of Mus validus except that 

 the audital bullae are exceedingly large and dilated, most nearly 

 resembling in this respect that of the smaller Mm annandalei, Bonh. 



Colour. — General colour above a grizzle of black and deep buff 

 (pale ochraceous buff), darker posteriorly owing to the prevalence 

 of the long black-tipped bristles which are everywhere present and 

 which attain on the rump to a length of 40 m.m. Sides and limlis 

 paler and duller, due to the grey under-fur showing through and 

 to the absence of dark annulations to the hairs. Top of head and 

 face and also below eye blackish, distinctly darker than cheeks and 

 nock. Bflow pure buffy-white, sharply separated from the upper-parts, 

 extending to the wrists and to the upper lip behind and below 

 whiskers, but not to the ankles which are like the outer side of thigh. 

 Along the sides of the abdomen a narrow stripe about 4 m.m. broad of 

 pure buff. Hands and feet clothed with short dark-brown hairs. 

 In males a brown prescrotal patch. Tail stout and unicolour, black, 

 longer than head and body. Ear rounded. 



Skull. — Skull like that of Mas validus, but less robust and 

 slenderer. Audital bullae deeper anteriorly than posteriorly : much 

 larger, rounder and more dilated than those of any other local rat. 



Measureme.vts. — Collector's external measurements: head and 

 l>ody, 222 ; tail, 251 ; hind-foot, 41 ; ear, 23. Cranial measurements : 



