RAT-KANGAROOS. 249 
The little banded wallaby (Lagostrophus fasciatus), of Western 
Australia, which is about the size of a hare, and is easily recognised 
by the dark transverse bands crossing the hind-quarters, forms the single re- 
presentative of a genus. It is specially characterised by the presence of long 
bristly hairs on the hind-feet, which completely conceal the claws. The muzzle 
is naked; and the ears are small and rounded. The skull is characterised by 
its narrow muzzle, and inflated auditory bulla; while there is no tusk, the two 
series of upper incisor teeth meet in an angle, and the two halves of the lower 
jaw are welded together at their union. These pretty little wallabies inhabit the 
serub-jungle and the margins of swamps on the west coast of Australia and the 
small adjacent islands. On the islands they form tunnels beneath the dense bushes 
by gnawing off the lower branches on certain lines; and they can only be beaten 
out from their cover by the aid of dogs. On the mainland they are said to skulk 
in the open like hares. 
The whole of the members of the family hitherto considered 
form a single subfamily primarily characterised by the circumstance 
that the three incisor teeth of the upper jaw are of nearly equal height, while the 
tusk, or canine tooth, if present at all, is very minute. We now come to a second 
group or subfamily, including a number of small forms known as rat-kangaroos 
or potoroos, which differ in many important respects from the preceding. These 
creatures, none of which are larger than an ordinary rabbit, are characterised by 
having the first incisor tooth on each side of the upper jaw (as shown in the figures 
on pp. 237 and 239) considerably taller than either of the others, and narrow and 
eurved in form; while there is always a rather large and blunted upper tusk. 
Then, again, whereas in the preceding subfamily, with the exception of Miiller’s 
kangaroo and its allies, the permanent premolar tooth is comparatively short from 
front to back, in the group under consideration the same tooth, as shown in the 
aforesaid figures, is much elongated in this direction, and has a straight cutting- 
edge, and its two surfaces generally marked by vertical grooves and ridges. 
Sometimes, moreover, the same tooth may be bent slightly outwards, instead of 
forming a continuation of the line of the molars. The latter have blunt tubercles 
at their four angles, instead of complete transverse ridges; and the last of the 
series is, instead of being larger, always smaller than the one in front of it. The 
rat-kangaroos are further distinguished by their narrow fore-feet, in which the 
three middle toes are much longer than the other two, with long, narrow, and 
slightly-curved claws; whereas in the broader front paws of the preceding group, 
the whole five toes are nearly equal in length, and have highly-curved claws. All 
the rat-kangaroos have small rounded ears, and long furry tails, of which the 
extremities are partially prehensile in some of the species. Externally, the rat- 
kangaroos cannot well be distinguished in general appearance from some of the 
smaller short-eared representatives of the preceding group; and it is accordingly 
of prime importance that the foregoing distinctive characteristics should be 
thoroughly understood. The group comprises nine species, which are confined to 
Australia and Tasmania, and are divided into four genera. 
Common Rat- The common rat-kangaroo (Potorous tridactylus), that figured in 
Kangaroo. the illustration on the following page, may be taken as our representa- 
Banded Wallaby. 
Rat-Kangaroos. 
