The bats are, no doubt, much more numerous, but there is every reason to believe that whatever new land Mammalia man be discovered will belong to the marsupial order.

One of these is a true kangaroo, very similar to some of middle-sized kangaroos of Australia, and it is remarkable as being the first animal of the kind ever seen by Europeans.

It inhabits Mysol and the Aru Islands (an allied species being found in New Guinea), and was seen and described by Le Brun in 1714, from living specimens at Batavia.

A much more extraordinary creature is the tree-kangaroo, two species of which are known from New Guinea.

These animals do not differ very strikingly in form from the terrestrial kangaroos, and appear to be but imperfectly adapted to an arboreal life, as they move rather slowly, and do not seem to have a very secure footing on the limb of a tree.