Some naturalists think there are but two permanent species of the fox in the United States, namely, the gray fox and the red fox, though there are five or six varieties.  The gray fox, which is much smaller and less valuable than the red, is the Southern species, and is said to be rarely found north of Maryland, though in certain rocky localities along the Hudson it is common.

In the Southern States this fox is often hunted in the English fashion, namely, on horseback, the riders tearing through the country in pursuit till the animal is run down and caught.  This is the only fox that will tree.  When too closely pressed, instead of taking to a den or a hole, it climbs beyond the reach of the dogs in some small tree.

The red fox is the Northern species, and is rarely found farther south than the mountainous districts of Virginia.  In the Arctic regions it gives place to the Arctic fox, which most of the season is white.

The prairie fox, the cross fox, and the black or silver-gray fox seem only varieties of the red fox, as the black squirrel breeds from the gray, and the black woodchuck is found with the brown.  There is little to distinguish them from the red, except the color, though the prairie fox is said to be the larger of the two.

The cross fox is dark brown on its muzzle and extremities, with a cross of red and black on its shoulders and breast, which peculiarity of coloring, and not any trait in its character, gives it its name.  It is very rare, and few hunters have ever seen one.  The American Fur Company used to obtain annually from fifty to one hundred skins.  The skins formerly sold for twenty-five dollars, though I believe they now bring only about five dollars.

The black or silver-gray fox is the rarest of all, and its skin the most valuable.  The Indians used to estimate it equal to forty beaver skins.  The great fur companies seldom collect in a single season more than four or five skins at any one post.  Most of those of the American Fur Company come from the head-waters of the Mississippi.  One of the younger Audubons shot one in northern New York.  The fox had been seen and fired at many times by the hunters of the neighborhood, and had come to have the reputation of leading a charmed life, and of being invulnerable to anything but a silver bullet.  But Audubon brought her down (for it was a female) on the second trial.  She had a litter of young in the vicinity, which he also dug out, and found the nest to hold three black and four red ones, which fact settled the question with him that black and red often have the same parentage, and are in truth the same species.

The color of this fox, in a point-blank view, is black, but viewed at an angle it is a dark silvergray, whence has arisen the notion that the black and the silver-gray are distinct varieties.  The tip of the tail is always white.

In almost every neighborhood there are traditions of this fox, and it is the dream of young sportsmen; but I have yet to meet the person who has seen one.  I should go well to the north, into the British Possessions, if I were bent on obtaining a specimen.