RODEXTIA SCIURINAE SCIURUS FOSSOR. 265 



of the circumference, theentire under parts being pure white. There is not the slighest trace of any 

 darker line of separation on the flanks. The upper surface of the feet and exterior of the limbs 

 are like the back; the paws perhaps lighter, but still grizzled. The inner edge of the hind foot, 

 also, is nearly uniform dull whitish. The lower parts of the cheeks and side of the muzzle are 

 greyish white, less pure than on the belly. The woolly tuft at the base of the ear, and usually 

 the convexity or back of the ear itself, are light chestnut, forming a very conspicuous feature. 



The tail is a mixed gray, black and white. Beneath, it is grizzled ; above, black predomi 

 nates, with some white on the outside ; on the side the white is very conspicuous, forming a 

 distinct white border. The inferior hairs are grayish white, with four or five annulations of 

 black, about the width of their interspaces. The same condition prevails pretty much on the 

 rest of the tail, with the exception that the subterminal annulation is much broader and 

 entirely black, and on the sides the terminal white is also very long. 



There is no appreciable difference in a number of specimens of this squirrel before me from 

 different localities ; much less than usual in squirrels. One from Fort Tejon has a smaller body 

 in proportion to its tail than the rest ; but the skin has probably shrunk considerably in alco 

 hol, and the animal itself was quite young, as shown by the skull. This is the only one in 

 which there is no chestnut on or behind the ear, the woolly tuft there being dirty whitish. One 

 specimen (609) shows a slight wash of rusty on the back, and the hind feet are sooty black, 

 slightly grizzled. This is the most decided variation I have noticed. Winter specimens have 

 the soles hairy, except on the tubercles, while summer ones have them naked. 



Skull. The skull of this species appears rather more slen 'er and elongated than that of the 

 S. carolinensis or the fox squirrel of the Mississippi ; its closest relationships, as to shape, are 

 with the S. vulpinus, which it nearly equals in size. It has, however, a longer muzzle and the 

 zygomatic arch set further back. An old skull has four distinct upper molars and the stumps 

 of the anterior fifth one, broken down to the level of the socket. In several younger ones this 

 small molar is well developed and considerably larger than in S. carolinensis , the crown having 

 a compressed central tubercle and a distinct valley on either side. 



This species is mentioned by Lewis & Clark, under the name of "the large gray squirrel," as 

 occurring near the Dalles of the Columbia, and they fully appreciated its difference from the 

 squirrels of the eastern States. It is a little singular that an animal described with such detail 

 by these authors should not have been named by the earlier writers, like Ord, Rafinesque, 

 Harlan, and others, when all the other species mentioned in the narrative of the expedition 

 were so promptly introduced into the systems. 



I am not without a strong suspicion that the Sciurus leporinus of Audubon and Bachman 

 may prove to be the same with the S. fossor, in which case it will, of course, take precedence. 

 The only point in the description which cannot be readily referred to S. fossor of Peale is in the 

 color of the back, which is said to closely resemble that of the English hare (probably Lepus 

 timidus) in its brown tints. But for this I would be inclined to consider it as a young specimen 

 of S. fossor, as in the most immature one I have seen (480) the downy space on the back and 

 base of the ear was whitish instead of chestnut. Indeed, this same specimen I had unhesi 

 tatingly labelled S. leporinus before the opportunity was afforded of examining adult animals. 



This squirrel inhabits abundantly the whole mountain region of California, from San Diego 



as far north as the Columbia River at the Dalles ; it does not appear to cross this river. The 



extreme limit of its distribution south and east is not yet ascertained. As far as I can learn, 



however, it is the only large species found within the region inhabited by it ; and I have no 



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