The hands and feet are white. In both M. gouldii and M. macrurus the tip of the white tail is tufted, but the tail is not so well haired near its base, where the scales can be traced. The ears are moderate in size, and their outer surfaces are quite densely haired. The foreclaws are fairly large, and the hind foot is somewhat broad, with large claws. The skull is heavily built.
Females have four mammae.
They are nocturnal and arboreal but may descend to the ground to feed. By day they shelter in hollow trees. At times they live near wooden buildings and climb about the rafters at night. A nest, mainly of leaves and bark, may be located in a tree. One nest covering part of the main cavity of the trunk was found in a tree about 3.5 meters above the ground.