6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 60 



above, darker than general tone of back ; below buffy at root, then 

 yellowish-buff, then with band of brown; terminal half black above 

 and below. Underparts of body, limbs, and feet, white, with very 

 faint tinge of pale straw on arm pits and lower belly. Lips white. 



Skull and teeth. — Skull almost precisely like skulls of Mustela 

 erminea from Sweden. Teeth, especially upper molar, lower car- 

 nassial, and last lower molar, smaller than in erminea. 



Measurements of type.- — Head and body, 275 mm. ; tail vertebrae, 

 103 ; hind foot, without claws, 43. Skull : Condylobasal length, 47.6 ; 

 palatal length, 20; least interorbital constriction, 10.6; upper molar- 

 premolar row, 11 ; lower molar-premolar row, 12.5. 



Remarks. — This new stoat differs conspicuously from Mustela 

 erminea in the color of the upperparts, and appears to resemble in that 

 character the Mustela erminea ferghance of Thomas from Ferghana. 

 From the latter species it differs, however, in its much greater size, 

 less yellow in coloration below, the absence of a white spot behind 

 eye, and the much longer tail, as well as in other minor details. 



MY0T1S PETAX, sp. nov. 



Type from Kosh-Agatch, Chuisaya Steppe, Altai District, Siberia; 

 Altitude 7300 feet. No. 175 189, United States National Museum; 

 skin and skull; adult $. Collected July 30, 1912, by N. Hollister. 

 Orig. No. 4412. 



General characters. — Like Myotis daubentonii but slightly larger 

 and less reddish-brown ; skull larger and teeth actually smaller. 



Color of type. — Above sepia, lacking the reddish-brown tint of 

 daubentonii in good coat. Below white, the bases of hairs seal brown. 

 White of underparts extending on cheeks to base of cars. Wings 

 blackish-brown ; interfemoral membrane dark brown above, much 

 lighter below. 



Skull and teeth. — Skull larger than in M. daubentonii (longer and 

 with broader braincase, rostrum, and palate). Teeth smaller than in 

 daubentonii; narrower, but with tooth row of about same length. 



Measurements of type. — Head and bod}-, 55; tail vertebrae, 37; 

 hind foot, without claw, 10; forearm, 39.5. Skull: Greatest length, 

 14.5; zygomatic breadth, 9.2; least interorbital constriction, 4.2; 

 breadth of braincase, 7.6; upper tooth row, including incisors, 6.1. 



Remarks. — While this form may be found eventually to inter- 

 grade with true daubentonii, the relative size of skull and teeth, and 

 the marked differences of color pattern and tone, <.\v not warrant 

 considering it at present a geographical race of that species. The 

 type was captured in a house in Kosh-Agatch ; far from cliffs or trees, 

 on the steppe. 



