140 Jlille)'. — /Seven JVew Mats collected hi Slam. 



Specimens examined. — Eight, all taken at or near the type locality. 



Remarks. — Mus vociferans is the mainland representative of M. sahanus, 

 a rat quite unlike any of the other species known to occur on the Malay 

 Peninsula, and at present recorded from Borneo and the Natuna Islands 

 only. It is a very noisy animal; when trapped its loud cries so quickly 

 attract the smaller carnivores that perfect specimens are with difficulty 

 obtained. 



Mus ferreocanus sp. nov. 



Type adult female (.skin and skull) No. 8G,737 United States National 

 Museum, collected in the mountains of Trong, Lower Siam, at about 

 3000 ft. altitude, January 15, 1899. 



Characters. — Size large (hind foot aboiit 5(5; greatest length of skull, 53) 

 tail slightly longer than head and body, dark brown at base, whitish at 

 tip; ear long and narrow, its length greater than distance from eye to 

 nostril; fur composed almost exclusively of fine grooved bristles: general 

 color above bluish iron gray, beneath pure white: skull with slightly de- 

 veloped supraorbital ridges. 



Fur. — Underfur rather scant, not at all woolly except on belly. The 

 main bocjy of the fur is composed of fine grooved bristles, those on mid- 

 dle of back about 15 mm. in length. Interspersed with the bristles are 

 a few terete black hairs, 25-30 mm. in length. These are practically 

 confined to the back and rump, and are nowhere conspicuous. 



Color. — The color of this rat is difficult to describe with accuracy, as 

 the tints cannot be matched in Ridgway's Manual of Colors. The gen- 

 eral effect is a lustrous bluish iron gray, darker along middle of back, 

 paler and slightly drab-tinged on sides; everywhere frosted by the pale 

 glistening tips of the bristles, Avhich produce a sheen varying much with 

 different exposures to light. Cheeks washed with drab gray, muzzle 

 with seal brown. Underparts creamy white, this color extending down 

 inner side of front legs to wrists, and on hind legs nearly to ankles. Fur 

 of dorsal surface gray (Ridgway, PI. II, No. 8) at base, that of under- 

 parts white throughout. Ear dark brown; a small tuft of fine white 

 hairs immediately beneath orifice. Tail dark brown, the terminal fourth 

 dull white. Hind feet uniform sepia. Front feet sepia varied with didl 

 white. 



Tail. — The moderately long tail of this species is finely, inconspicu- 

 ously and somewhat irregularly annulated. At middle there are twelve 

 rings to the centimeter. The rings are divided by cross furrows into 

 scales longer than broad and with rounded corners. These scales, how- 

 ever, are scarcely noticeable to the unaided eye. The fine stiff hairs 

 that spring from the spaces between the rings are in length abotit one 

 half greater than width of ring, and are apparently not definitely ar- 

 ranged with regard to the scales. Near tip of tail the rings become nar- 

 rower and more indefinite and the hairs longer and less stiff, though 

 without forming any semblance of a pencil. 



