458 PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXVI. 



RHINOSCIURUS LATICAUDATUS (Miiller and Schlegel). 



1839-1844 Sciurm laticaadutus Muller and ScHLE(iEL, Verhandel. over de 

 natmirlijko^ Gew-hiedenis der Nederl. overzeesche bezittingen, p. 100; Pon- 

 tianak, Western Borneo. 

 An adult female was taken on Pulo Tuangku, Banjak Island.^, Fel)ru- 

 ary 15 1002. Total length, 360; head and body, 230; tail vertebrae, 

 130- hind foot, 46 (44). Skull: Greatest length, 59; basal length, 52; 

 basilar length, 49.4; palatal length, 31; diastema, 17; length of nasals, 

 21- breadth of both nasals together anteriorly, 6; least interorbital 

 breadth, 13; zygomatic breadth, 28.6; mandible, 35.6; maxillary tooth- 

 row (alveoli), 12; mandibular toothrow (alveoli), 10.4. '^ Uterus con- 

 tained one embryo the size of a pea. Mammas, 4." 



Family MURID.E. 



MUS SIMALURENSIS, new species. 



T!/pe.-Adn\t female (skin and skull). Cat. No. 114216, U.S.N.M. 

 Collected on Simalur Island December 14, 1901, by Dr. W. L. Abbott. 

 Original number, 1372. 



Chnracters.—Uke Mus pcmyiosus of the Butang Islands, hut rather 

 smaller; fur shorter and less coarse; color darker and less yellowish; 

 teeth smaller; mammte 10, as in other members of the group. 



^^//.._The fur is rather close and fine in texture, much more so 

 than that of 3fus jyanmMKs, though it contains many grooved bristles. 

 These, however, are scarcely more stiff than the longer terete hairs. 

 At middle of back the body of the fur is about 14 mm. in length, the 

 scattered long hairs exceeding this by about 6 mm. These long hairs 

 show no distinct tendency to increase in length on rump and lumbar 

 region. 



Color.— Bsick and sides a moderately coarse, but not very conspicu- 

 ous grizzle of })lack and dull ochraceous buff, the former a little im 

 excess on back, the latter distinctly so on sides, and tips of bristles 

 and longer hairs with metallic iridescence. Underparts buff, rather 

 lighter than that of Ridgway, and somewhat clouded by gray along 

 median line of chest. Feet dull brownish. Ears and tail uniform 

 dark brown. 



Skull and teeth.— The skull is larger than that of 3fu8 alexandrinus, 

 though of essentially the same form. In size it closely approaches 

 that of Mus pannosus, but the average length appears to be less than 

 in the Butang animal. In form the skulls of Mus simaluremis and 

 M. jxinnoxus closely resemble each other, except that the rostrum is 

 more slender in the Simalur rat and the incisive foramina are longer, 

 narrower, and more nearly parallel-sided. Teeth as in Mus patwosiis, 

 but smaller. 

 Measurements.— Extavna] measurements of type: Total length, 402; 



