188 Miller Mammal* from Lankaici (vnd 



Mus vociferans lancavensis subsp. nov. 



Type. Adult female (skin and skull), No. 104,173 United States Na 

 tional Museum. Collected on Pulo Lanktiwi, December 6, 1890. Origi 

 nal number 122. 



Characters. Not as large as Mus vociferans vociferans from Trong, 

 Lower Siam; color more conspicuously ochraceous; tail with less brown 

 on dorsal surface; skull with median portion of parietals more elevated 

 above general outline of braincase. 



Color. The color so closely resembles that of true Mus vociferans that 

 no detailed description is necessary. When series of specimens are com 

 pared, however, it is at once seen that those from Pulo Lankawi are dis 

 tinctly more yellow than those from the type locality of the species. 

 The difference is due in part to a slight reduction in the number of dark 

 hairs on the back in the insular animal, but to a certain extent also to a 

 change in the ochraceous ground color. The latter, particularly on the 

 cheeks, flanks, and outer side of thighs, is visibly though faintly more 

 yellow than in the Trong specimens. Underparts cream-buff. Tail 

 whitish above and below distally, bicolor at base. The brown dorsal 

 area scarcely reaches middle of tail, while in true Mil* vociferans it ex 

 tends beyond middle and often nearly to tip. 



Skull and teeth. In size and general form the skull agrees with that 

 of Mus vociferans vociferans, but when viewed from the side a slight 

 though very constant difference in the form of the braincase becomes 

 apparent. In both animals the middle portion of the parietals is con 

 vex, rising as a distinct though low prominence above the level of the in- 

 terparietal and that of the frontals. This convexity is so exaggerated in 

 Mus vociferans lancavensis that skulls are easily recognized either by 

 sight or touch. 



Teeth similar to those of true Mus vociferans. 



Measurements. External measurements of type: total length, 520; 

 head and body, 209*; tail vertebrae, 311*; hind foot, 45; hind foot with 

 out claws, 42. Average of five specimens, including the type: total 

 length, 543 (520-559); head and body, 222 (209-229); tail vertebra?, 321 

 (311-330); hind foot, 46 (45-47); hind foot without claws, 43 (42-44). 



Specimens examined. Five skins and nine skulls, all from the type lo 

 cality. 



Remarks. While this insular race is distinguished from true Mus vo 

 ciferans by no one constant character the sum of its peculiarities are 

 enough to make it readily distinguishable. The slight difference in size 

 is chiefly due to the shorter tail of the insular form.f 



^Collector's measurement. 



fin seven topotypes of Mus vociferans the tail averages 342 mm., with 

 extremes of 323 mm. and 380 mm. 



