450 Mr. O. Thomas on the 



Mr. Hose has contributed some from Mounts Dulit and Mulu 

 and the lowlands of Baram, I am enabled to work out the 

 whole series somewhat more satisfactorily. 



But even now it has been found impossible to do move than 

 give a rough synopsis of the species as yet recognized to 

 occur in Borneo, without making any observations on the 

 Murine fauna of the other great East-Indian Islands, where 

 no doubt many of the same species also occur. 



Similar or better series will be needed from those islands 

 before anything of the sort can be attempted. 



The characters given in this synopsis are such as may be 

 observed by any one on the spot, with good skins for exam- 

 ination, and do not need any technical knowledge for their 

 recognition beyond the power of distinguishing adult from 

 young specimens. Detailed technical descriptions of the 

 new species are, of course, appended. 



Although it is hoped that the present paper marks an 

 advance on our previous limited knowledge of these animals, 

 yet there is clearly an enormous amount more to be learnt as 

 regards their ranges, vertical and horizontal, their sexual and 

 seasonal differences, and many other points, on most of which 

 we are entirely ignorant. For this purpose we want infinitely 

 more material and that better collected, especially in the 

 form of skins, with perfect skulls, and with the exact localities, 

 altitudes, and flesh-measurements carefully marked on the 

 labels. These remarks, if true of Borneo, are much more 

 so as regards the other great islands of the East Indies, from 

 all of which good material is urgently needed. 



Bough Synopsis of the Species of Mus known to occur 

 in Borneo. * 



1. Mus infraluteusy Thos. 



Size very large, form thick and heavy ; hind foot about 

 50 millim.* Tail about equal to head and body, black, short- 

 haired. Fur soft, but with longer harsher bristles inter- 

 mixed. Colour hoary blackish grey ; belly dirty greyish buff, 

 not sharply defined. Hands and feet blackish. 



Mount Kina Balu (Whitehead, Everett). 



a Tankulom " of Dusuns (Everett). 



2. Mus Muelleri, Jent. 



Size large, form normal; hind foot about 42 millim. Tail 

 rather longer than head and body, brown, short-haired. Fur 



* Measured from heel to tip of longest toe, without claw. 



