426 PROCYONIDAE CHAP. 
cross stripes (save rings on the tail), which are so common a 
feature of the coloration of the Cat-lke forms. 
In bracketing together the three families which are described 
in the following pages, emphasis is laid upon a number of un- 
doubtedly common features. Palaeontology seems, however, to 
suggest that the Mustelidae come nearer to the Viverridae. That 
the Bears and Dogs are connected by extinct annectent genera 
does not interfere with their present distinctness. 
The systematic arrangement of these Carnivora is not easy. 
It may be useful, however, to give a method of arrangement for 
the convenient placing of the genera. 
The most primitive group is perhaps that of the true Bears, 
family Ursidae; for in them the molars are two above and 
three below, and have thus not become diminished in number 
as in some of the other members of the order. Moreover, the 
Bears have lobate kidneys, which character, often occurring in 
the young of animals which when adult have smooth kidneys, 
may be looked upon as a primitive character. The feet further- 
more are completely plantigrade. This family will contain only 
three genera, Ursus, Melursus, and Aeluropus. 
Next comes the family Procyonidae, in several members of 
which one molar is lost below, though in others the more 
archaic formula is retained. The kidneys are simple. This 
family contains the American genera Procyon, Nasua, Bassariscus, 
Bassaricyon, Cercoleptes, and the Old-World form Aelurus. 
The third family, Mustelidae, has the molar formula reduced to 
+ ori. The kidneys are simple except in the Otters. To this 
family are assigned the following genera :—Arctonyx, Conepatus, 
Meles, Mephitis, Taxidea, Mydaus, Mellivora, Helictis, Ictonyx, 
Mustela, Galictis, Grisonia, Putorius, Gulo, and the aquatic Lutra, 
Enhydris, and Aonyx. 
Fam. 6. Procyonidae——This family is mainly American in 
range, the genus Ae/urus alone being a native of the Old World. 
But Zittel would include with the genera of this family the 
Viverrine and Oriental genus <Arctictis, a proceeding which is 
perhaps hardly admissible, though the occasional absence of a 
caecum in that animal is so far in favour of such an alliance. 
The largely vegetable nature of its food and its arboreal habits 
cause a certain amount of likeness to some of the members of 
the present group of Carnivores. The Procyonidae have two 
