2fi 



U. S. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT^ 



white, with a slight tinge of brown ; the color well contrasted, against the back. The feet and 

 under surface of the tail are whitish ; the upper surface of the tail like the back ; the entire 

 tip dusky. The teeth are light chestnut at the point. 



The upper preraolar teeth are imbricated anteriorly, and diminish from the first to the fourth 

 with considerable regularity; the difference between the third and second being much less 

 appreciable than in S. cooperi. 



The weight of a specimen of this species, as given by Linsley, is 47 grains ; that of number 

 1696, however, of the accompanying table, amounted only to 37 grains. 



For the measurements of the skull of this species, see the table under the head of 8. cooperi. 



There are some slight variations from the above characteristics in different specimens. Thus, 

 the tail is sometimes a little longer or shorter. The ear varies somewhat in size. Sometimes 

 the chestnut of the back is of a browner or darker shade a characteristic, probably, of the 

 winter pelage. In immature specimens, the tail is almost naked, and the tips of the teeth with 

 little or no color, even when of full size. 



This species is perhaps more nearly related to S. forsteri than to S. cooperi, although resem 

 bling the latter most in color. In size it occupies an intermediate position, as also in the pro 

 portional length of the tail. 



Its distribution I have not yet ascertained with precision, though it is known to range from 

 eastern Massachusetts to Cleveland, Ohio, and as far north as Burlington, Vermont. 



List of specimens and measurements. 



