What is the difference between a kangaroo and a wallaby?

   Most wallabies are the size of a hare or slightly larger, but the brush or scrub wallabies are up to 3 ft long in head and body, with a tail 2½ ft long and a weight of up to 50 Ib. There are three species of hare wallaby, which are greyish brown with some red in places. The single species of bandea hare wallaby is greyish with many dark bands across the back, from the nape to the base of the tail. The three species of nail-tailed wallabies are mainly grey but the eleven species of scrub wallaby are sandy to reddish brown. The five New Guinea forest wallabies are greyish brown to blackish brown.
   The distinction between kangaroos and wallabies is hard tofix satisfactorily. In general, wallabies are small, looking like miniature kangaroos, but some are large an these are sometimes callea 'kangaroos' locally.