252 U. 8. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



throughout, and all these phases of size and coloration have had different names assigned to 

 them. 



The western fox squirrel is among the largest of the American species, heing only exceeded 

 by the fox squirrels of the Atlantic States ; it is, however, a little smaller than the California 

 gray squirrel. 



The head of this species is rather narrower than that of the Pennsylvania fox squirrel, S. 

 cinereus, the muzzle longer and more attenuated, the ears higher, narrower, and projecting 

 more above the fur of the nape. The back of the ear is coated, generally, with compact short 

 hairs, though sometimes these lengthen, especially in winter, so as to form slight tufts ; there 

 is also more or less of a woolly tuft adjacent to the base of the ear behind. 



The tail of this species is very long and ample, the vertebral portion shorter than the head 

 and body ; with the hairs it is longer. In length of tail this species exceeds the S. cinereus. 



The feet are large, the soles naked in summer, more or less densely furred in winter, agreeing 

 in this respect with nearly all the North American species. 



The colors of this squirrel, as already stated, vary very much, although the foxy type 

 generally predominates. The most usual condition is a grizzled black gray and rusty above, the 

 whole under parts of body and tail uniformly yellowish red, without any annulation. The 

 lateral and superior hairs of the tail are, however, variously annulated. The shade of color in 

 this respect varies very much. 



The more prominent varieties of the species are as follows : 



1. The typical coloration as described, with the under parts uniform foxy, &C. 1 



2. The colors above and on the tail as described ; the whole under surfaces, with the inside 

 of the limbs, uniformly black, without annulation. (Nos. 179, Eacine ; 1983, Illinois ; 1346, 

 St. Louis.) 



3. Similar to the preceding ; but the hairs of the" under parts annulated with rusty, although 

 the black greatly preponderates. (No. 2352, from Iowa.) 



4. A single specimen, No. 2300, received from Prairie Mer Rouge, with a number of fox- 

 colored skins, exactly similar in all specific features, agrees perfectly with the description of S. 

 auduboni, of Bachman, in having the upper parts more dusky, the belly of a dark chocolate 

 brown, all the hairs annulated with black, as on the back. The hairs of the tail are more finely 

 annulated than in the red variety. 



I have never seen any specimens of this species pure grizzled gray above, without a mixture of 

 red or pure white beneath, as in S. vulpinus and cinereus ; nor, as in the former species, is the 

 color, as far as my observations extend, ever entirely black, with the hairs unicolor to the roots, 

 as in S. vulpinus. The species, therefore, does not present as great extremes in coloration as do 

 the two others just mentioned. 



I am not prepared to say that there may not be two fox-colored squirrels in the Mississippi 

 Valley, one more southern than the other ; but investigations conducted mainly on dried 

 specimens have not satisfied me that there are more than one. I have not the slightest doubt, 



1 A winter specimen from Fort Des Moines, Iowa, (2553,) baa the fur much fuller and softer than in any others I have 

 ever seen, with a peculiar tinge of purplish red beneath, especially on the tail. In a summer specimen from the same 

 locality (2695) the color is a light yellow all over, paler beneath, the tips of the long hairs above nearly white. The hairs 

 of the tail are of a darker shade or a yellowish rusty. All the caudal hairs, both above and below, are perfectly uniform 

 to the roots, without any annulation whatever ; nor is there any annulation on the back, the tips of the hairs only being 

 lighter. 



