miller] seventy new MALAYAN MAMMALS 35 



laterally and along median line of chest. Feet hair-brown. Ears 

 and tail uniform blackish brown. 



Skull and teeth. — While of about the same length as that of Mus 

 siantanieus the skull differs from that of the Anamba rat, as well as 

 all other members of the group, in its very heavily built rostrum 

 and anterior zygomatic roots. The plate forming outer wall of 

 infraorbital foramen is much wider than in any other species of 

 approximately equal size, and its upper margin is so flaring that the 

 foramen is a very conspicuous feature of the skull when viewed from 

 above. Audital bullae unusually large, subglobular in outline when 

 skull is viewed from below. Teeth in no way peculiar. 



Measurements. — Measurements of type : total length, 379 ; head 

 and body, 190; tail vertebrae, 189; hind foot, 36 (34); ear from 

 meatus, 19.6; ear from crown, 13; width of ear, 14; skull, greatest 

 length, 41 ; basal length, 37.4 ; zygomatic breadth, 20.6 ; interorbital 

 constriction, 7. 



Specimens examined. — Six (three in alcohol), all from St. Julian 

 Island. 



Remarks. — This easily recognizable member of the Mus rattus 

 group is very different from the large Mus tamhelanicus, its nearest 

 geographical ally. In size it closely agrees with Mus siantanieus, 

 but the cranial characters of the two species are very different. 



MUS GILBIVENTER sp. nov. 



Type. — Adult male (skin and skull), No. 104,153, United States 

 National Museum. Collected on Sullivan Island, Mergui Archi- 

 pelago, February 2, 1900, by Dr. W. L. Abbott. Original number, 



295- 



Characters. — Similar to Mus cremoriv enter but with coarse, spiny 

 fur resembling in quality that of the members of the surifer group. 



Color. — The elements of the color are exactly as in Mus cremori- 

 venter,^ except that the spines on the back and sides are strongly 

 tinged with cream-buff. These spines everywhere appear conspicu- 

 ously on the surface instead of being completely hidden by the softer 

 elements of the fur as is the case in Mus cremoriventer. The effect 

 on the general color is to produce a peculiar variegated grizzle of 

 ochraceous, light yellowish horn-color, and blackish brown, notice- 

 ably* different from the more uniform ochraceous of the related spe- 

 cies, and suggesting some of the members of the surifer group. 

 Cheeks and narrow line along sides bright, clear ochraceous. Belly 

 and inner surface of legs cream-buff rather vellower than that of 



^ See Proc. Biol. Soc. Washington, xiii, p. 144, April 21, 1900. 



