MAMMALS OANID^VULPES VULGARIS PENNSYLVANIOUS. 53 



tips. Sides of the head and neck, and of the body itself, a varying shade of 

 feiTiigineous or reddish-yellow; inner surface of ears the same. Black of 

 under parts frequently ending on the chest, when the rest and the parts 

 about the root of the tail below are pale rusty. Shades into the preceding 

 and following styles by insensible degrees. This is Cauls or Vidpcs fulrns 

 var. decussatus, of AUTHORS ; RICH., Fn. B.-A., i, 1829, J.)3 ; AUD. & BACH., i, 

 1849,45, pi. 6; Bn., 124. 



Melanism complete or very nearly so results in 



The BLACK or SILVER-GRAY Fox (argentatus). Black ; tail usually con- 

 spicuously white-tipped ; more or fewer of the hairs, especially of the back 

 and flanks, tipped with white or gray, producing a "silvered" appearance. 

 Perfectly black animals are extremely rare and correspondingly high- 

 priced. This style of pelage is chiefly produced in high latitudes. C. or 

 V. argentatus, or fulvus var. ari/nttt/t/tx, of AUTHORS ; RICH., Fn. B.-A., 1829, 

 i, 94; AUD. & BACH., iii, 1853, 70, pi. 116; BD., 124. 



Lieut W. L. Marshall reports having seen a fox which he supposed to 

 be of this variety in New Mexico. If his identification is correct, this fact 

 would extend the limit of the animal very far to the southward of its ordi- 

 nary range. 



Dimensions of any of the varieties. Nose to root of tail, 2-2i feet ; tail to end of 

 boues, 12-15 iucbes ; to etui of liairs, 15-19 incbes. Ear, 2i-2^ inches bigb, Ileigbt at 

 shoulders rather over 1 foot. Skull about 5 inches long by 3 inches in greatest width. 



While the Cross and Black or Silver Foxes are usually considered as 

 different "varieties", they are not such, in the classificatory sense of that term, 

 any more than are the red, black, or white wolves, the black marmots, 

 squirrels, etc. The proof of this is in the fact that one or both of the 

 " varieties " occur in the same litter of whelps from normally-colored parents. 

 They have no special geographical distribution, although, on the whole, both 

 kinds are rather northerly than otherwise, the Silver Fox especially so. 

 It does not appear to be ascertained exactly how far the styles of pelage 

 tend to perpetuate themselves, that is to say, in what proportion of cases a 

 cross will produce a cross litter, or a black a black litter ; but the inter- 

 breeding of the several varieties, and their purely accidental origin from 

 parents of the normal coloration, are incontestable. 



