SCIUUID^-SCIUROPTERCS VOLUCELLA. 



G59 



scarcely darker or more fulvous than the ventral surface of the body; again, 

 and more frequently, the lower surface of the tail is nearly as dark as the 

 dorsal surface of the body, from which it differs only slightly in lint. As 

 already noticed, tlie edges and terminal portion of tlu", lower surface of the 

 tail are occasionally strongly dusky. Commonly, the eye is encircled by a 

 narrow dusky ring, and there is a dusky spot in front of the eye; but some- 

 times these markings (in light-colored specimens) are wholly obsolete 

 Occasionally, there is a whitish spot at the posterior base of the ear, sometimes 

 conspicuously noticeable, while in the majority of instances no such marking 

 is clearly distinguishable. Also, in southern specimens, the pelage of the 

 lower surface is wholly white to the base; in others, the basal portion is 

 dusky, as is generally the case in northern specimens, in some of which only 

 merely the surface is whitish. 



Doubtless, the small amount of variation in color with locality, apparent 

 in this grou^, as in the Hares (see antea, p. 268), is in part owing to mode 

 of life, these animals being not only nocturnal, but habitually passing the 

 day-light concealed in hollow trees. They are hence apparently less exposed 

 to the influences most active in modifying coloration. 



As already intimated, the habitat of this species embraces nearly the 

 whole of the North American continent. Its range to the northward extends 

 apparently to the forest limit, there being specimens in the collection from 

 Labrador, the vicinity of Great Slave Lake, Fort Liard, and Alaska. There 

 are also specimens from Georgia, Mississippi, and Louisiana. It is well known 

 as an inhabitant of Mexico, and Mr. Salvin collected it at Dueflas, Guatemala. 

 Mr. Tomes refers to his specimens as having the fur a little coarser, and the 

 color every w hdr'» more rufous, than in gpecimens from the United States.* 

 Examples have been received from so 'nany parts oC the interior, as well as 

 from the Pacific coast, that it may be considered as presumably dispersed 

 throughout the wooded portions of the continent. Even where it is common, 

 it is a species not often observed, owing to its nocturnal habits. Audubon 

 and Bachman, in their very interesting biography of this species, speak of it 

 as being to some extent gregarious. 



The great amount of geographical variation in size presented by this 

 species has led to the recognition of several supposed species. As early as 



< Pme. ZoSI. Soc. Lond. 1801, |>. SSI. 



