386 



OAKNIVOEA 



the two colours straight and definite, extending along middle of 

 sides of body and neck and passing a little below ear and eye to 

 lower edge of muzzle pad, normally leaving upper lip white ; ear 

 brown, the rim whitish ; no dark spot behind angle of mouth ; 

 tail with terminal fifth and entire pencil black, elsewhere 

 concolor with back except for an ill-defined yellowish or whitish 

 median area which occasionally extends along under surface from 

 base toward or to black tip. In white winter pelage the entire 

 animal is white or whitish (often tinged with yellow), with the 



FlO. 81. 

 Mustela ei'minea. Nat. size. 



exception of the black area of the tail, which remains as in the 

 dark coat. 



Skull. — In general appearance the skull resembles that of 

 Mustela putorius (p. 421). This is especially true of the dorsal 

 profile, the form of the palate, rostrum and interorbital region, in 

 all of which the differences between the two animals are very slight. 

 Breadth of rostrum over canines rarely equal to least interorbital 

 width. Position of anteorbital foramen as in M. putorius, but 

 orifice relatively larger, the width of plate separating it from 



