402 ME. OLDFIELD THOMAS ON MAMMALS 



Mus DECUMAXUS Pall., var. 



a. Moiite Data, Luzon, Feb. 1895. 



This is a Eat so similar to some of the forms of Mus decumanus that, like the 

 Felis domestica above referred to, I can only suppose it to be the slightly modified 

 descendant of introduced examples. 



Mus RATTUS L., var. 



a. ? . Negros, 6500 feet. 



b. S. Mindoro, coast-level, Dec. 1895. 



The single specimen of the Miis rattus group from Negros seems sufficiently like the 

 Bornean variety to be provisionally referred to it. In many ways it has more the 

 aspect of some of the Indian forms of the species, such as M. rattus rufescens, than 

 any other Philippine or Bornean Rat that I have seen. 



A coast-level example from Mindoro may also be placed here. Its differences from 

 the highland Mus mindorensis are very striking. 



Mus MINDORENSIS Sp. n.^ 



a-e. 5 sks. Monte Dulangan, Mindoro, 5000 feet, Dec. 1895. 



A Rat of the group of Mus rattus, apparently forming a peculiar insular race. 

 Size of Mus rattus or rather smaller. Fur straight, sleek, and shining. General 

 colour very dark as compared with the ordinary eastern forms of the group, Mus 

 neglectus, &c. ; back a dark finely grizzled brown, the grizzling much finer than usual. 

 The light colour in the grizzling is a deep orange, becoming rather more yellowish on 

 the sides. Under surface whitish or dirty slaty grey, not defined from the upper 

 colour, and not unlike in tone that of typical house-haunting specimens of Mus 

 musculus. Face uniformly dark like the body, hairs round base of ears behind nearly 

 black. Ears rather short, almost naked, the hairs so minute that a lens is needed to 

 see them at all. Hands and feet blackish above, the digits scarcely paler. Tail 

 decidedly shorter than the head and body, smooth, very thinly haired, almost naked, 

 finely scaled (about 10 rings to the cm.), uniformly black above and below. 



Skull very uniform in character throughout the series. Brain-case rounded, swollen. 

 Supraorbital edges with the usual ridges rather weakly developed, and scarcely to be 

 distinguished on the posterior half of the parietals. Interparietal large, its anterior 

 edge slightly curved forward. Palatal foramina large and well open, reaching pos- 

 teriorly just to the level of the front edge of the anterior root of m.^. Posterior edge 

 of palate broad, squarish. Bullae rather smaller than in typical Mus rattus. 

 Dimensions of the type, an adult male in skin : — 

 Head and body 190 millim. ; tail 163 ; hind foot (moistened) 32"5. 



' Preliminary diagnosis in Minutes of P. Z. S. for June 15, 1897 (published Juue 19). 



