1903.] Allen, Mammals from Northeast Siberia. 169 



Eight of the Marco va skins represent the usual red phase, 

 while the other is a 'cross ' fox. In the red phase the general 

 color above varies from light to dark red, lighter and brighter 

 anteriorly, with a slight mixture of gray on the top of the 

 head and lower back ; the apical half of the ears is deep black ; 

 the anterior surface of the feet and apical half of the fore leg 

 is black or blackish, mixed more or less with rufous, as is the 

 upper surface of the hind feet, where the black extends up 

 from one third to two thirds the length of the tarsus, narrow- 

 ing proximally; the upper surface, and sometimes the lateral 

 surface of the tail is conspicuously washed with black, with 

 the extreme tip white. The ventral surface is quite variable 

 in respect to the amount of white present, which covers the 

 sides of the upper lip, the chin, throat, and breast, with the 

 underfur of the throat and breast more or less slaty black; 

 there is often a less well-defined whitish area over the extreme 

 posterior ventral surface, and sometimes an irregular whitish 

 median band connects the broad white area of the throat and 

 breast with the smaller white anal area. 



In the ' cross ' specimen the whole ventral surface is black, 

 deep black on the chin, throat, and breast, and brownish 

 black over the rest of the ventral surface ; edges of the upper lip , 

 and the sides of the face in front of the eyes also black, and 

 the feet and limbs are more extensively brownish black than 

 in the red phase. The dorsal surface is dark reddish brown 

 varied posteriorly with gray, not yellow as in the Alaskan 

 ' cross ' fox. The tail is also more heavily washed with black, 

 with, however, the usual white tip. The sides of the shoulders 

 and chest, the sides of the neck, and the area at the anterior 

 base of the ears, and at the sides of the base of the tail, is 

 much lighter than the general coloration, being in this ex- 

 ample bright yellowish rufous, becoming rich orange rufous at 

 the anterior base of the ears, but lightening to pale yellow at 

 the sides of the base of the tail. 



The following are the measurements of the series of skulls 

 from Marcova.: 



