234 MR. O. THOMAS ON THE [Apr. 16, 



head 18, breadth 18 ; heel to front of last foot-pad 23 ; length of 

 last foot-pad /"O. 



Skull : tip of nasals to centre of fronto-parietal suture (" bregma ") 

 3C millim. ; nasals, length 21, greatest breadth 6'0 ; interorbital 

 breadth 77 ; outer wall of infraorbital foramen, length 4*7 ; palate, 

 length 26*5 ; length of palatal foramen 7*9 ; diastema 13-6 ; length 

 of upper molar series O"-!. 



Dimensions of a fine female in spirit, preserved in the Museo 

 Civico, Genoa : — Head and body 230 ; tail 393 ; hind foot 49 ; ear 

 20 ; heel to front of last foot-pad 25 ; length of last foot-pad 8'8. 



This spirit-specimen was obtained by Signor Beccari at Sungei 

 Bulu, W. Sumatra, thus affording another instance of the relationship 

 between the mountain-faunas of Sumatra and Borneo. Its examin- 

 ation, which I owe to the kindness of my friend the Marquis of 

 Doria, has enabled me to add certain particulars, only observable in 

 spirit-specimens, to the original description of this species. 



Mus sabaniis belongs to a well-marked group of Rats which contains 

 Musjerdoni, Ely., Al. niveiventer, Hodgs., M. coxingi, Sw'inh., M. ed- 

 wurdsi, Thos., M. hellwaldi, Jent., Ji. alticola, Thos., and others. 

 These species are, however, all very much smaller than it is, with one 

 exception, M. edwardsi, which is as much larger, and not one of 

 them has a tail of anything like the extraordinary length of that of 

 Mus sabanus. 



One species, indeed, also a native of Borneo, has a certain super- 

 ficial resemblance to the present one, altliough belonging to quite a 

 different group of Rats. This is M. muelleri, Jent., of about the same 

 size, and with a nearly equally long tail ; but it may be readily 

 distinguished by its coarse Mus decumamcs-like fur, yellowish instead 

 of rufous coloration, the less sharply defined white underside, and 

 by the quite uniformly brown-haired feet and tail. 



16. Mus LEPTURUS, Jent. 



a. Ad. 



b. Inim. 3000 feet. 24/3/88. 



Described by Dr. Jentink from Javan examples now in the Leyden 

 Museum. 



17. Mus ALTICOLA, Thos. Ann. Mag. N. H. (6) ii. p. 408 



(1888). 



a, b. c? ? . 8600 feet. 24/2/88. 5 . Type. 



Fur mixed with flexible spines both above and below. General 

 colour above a peculiar bluish grey, not speckled or grizzled, darker 

 along the median line. Dorsal hairs and spines creamy white 

 basally, gradually darkening to grey terminally. Underside pale 

 yellowish white, the hairs and spines uniformly of this colour to 

 their bases ;. the line of demarcation on the sides not very sharply 

 defined. Hands and feet white, the hairs short and fine, fifth bind 

 toe (without claw) reaching nearly to the end of the first phalanx 

 of the fourth. Tail finely rmged, the rings averaging about 1 or 



