The species are distinguished from one another chiefly by the number of bands on the trunk of the body, between the shield on the fore-shoulders, and that on the rump. Baron Cuvier, however, divides the whole genus into five small groups,—distinguishing one from another by the number and form of their teeth and claws.
The great armadillo (Dasypus gigas) has enormous claws and unequal toes, with twenty-four broad teeth on both sides of its jaws. It measures, exclusive of the tail, nearly three feet in length.
Darwin describes another, living on very dry soil, the pechy (Dasypus minutus), which wanders by day over the open plains, and feeds on beetles, leaves, roots, and even small snakes. So rapidly does it burrow, that scarcely is one seen before its hind-quarters disappear in the sand. It likewise tries to escape notice by squatting down close to the ground.
The Opossum.
There are numerous species of opossum, most of them marsupial, in the Brazils, where they take the place of the shrews of Europe. They are very destructive to poultry. One of the species is aquatic, and has webbed feet. The terrestrial species are nocturnal. They sleep during the day in the hollows of trees, and come forth at night to prey on birds in their roosting-places. Some live entirely on trees.
The Crab-Eating Opossum.
The crab-eating opossum is a curious creature, about ten inches in length; with a prehensile tail, fifteen inches long, in addition. It has a somewhat pointed nose, and a darkish fur. When born, the young are transferred by the mother to her cradle pouch, where they live for some weeks before they are sufficiently developed to venture abroad.
The creature is formed especially for living among the trees, about which it moves with the activity of a monkey. It advances carefully, always entwining its tail round one branch before venturing on to another.
The crabs and other crustaceans on which it lives—from which circumstance it obtains its name—are found on low marshy soils, in the neighbourhood of which these species exist.