2 Proceedings of the Biological Society of Washington . 



question, but michnoi is at any rate a different animal from 

 either of the forms here described. 



Mustela lineiventer sp. nov. 



Type from Tchegan-Burgazi Pass, Little Altai, Siberia; 9000 feet. 

 United States National Museum No. 175,440, cf adult, skin and skull. 

 Collected July 10, 1912, by N. Hollister. Grig. No. 4281. 



General characters. — A polecat related to larvata, with light colored 

 head; tail with hlack only on tip; and underparts with pectoral and 

 inguinal black areas connected by only a narrow median stripe of light 

 brown, the middle underparts of body otherwise clear cream-burl'. 



Color of type. — Ring around nose pad, lips, chin, upper throat, cheeks, 

 and area between eye and ear white, very slightly mixed with brownish. 

 Ring around eyes, mask across forehead, and tufts in front of ears dark 

 bister. Top of head drab-gray (mixed white, buff and gray); nape and 

 upper back between shoulders rich golden-buff, then paler buff (with 

 more mixture of white); lower back with long black-tipped overlying 

 hairs. Tail brownish-buff above and below, with bushy black tip. Lower 

 throat, breast, arms to shoulders, anal and inguinal regions, and legs to 

 hips pure black ; the two areas of black connected by a narrow median 

 line of brownish. Rest of underparts and sides forward burly-white. 



Measurements of type and two topotypes, all fully adult: 



Head and body 480 



Tail vertebne 



Hind foot, without claws 



Skulls 



Condylobasal length 



Zygomatic breadtb 



Least postorbital breadth 



Upper molar-premolar row 



Length of mandible 



Lower molar-premolar row 



Mustela tiarata sp. nov. 



Type from Chiu-ning-chow, 150 miles east of Lanchow, Kansu, China; 

 5500 feet. United States National Museum No. 155,160, skin and skull 

 of immature d 1 (permanent dentition in place but basal and nasal sutures 

 open). Collected July 24, 1909, by Arthur de C. Sowerby. Orig. No. 196. 



General characters. — A larvata-tike polecat with face and top of head 

 dark bister, the mask very faintly defined or entirely obscured owing to 

 the uniformity of color. Tail with basal third brown, terminal two-thirds 



