The field mouse and rabbits are rodentia, the deer ungulata, the kangaroos marsupialia.

It is well known that none above the marsupialia, or pouched animals, are native to it.

Generally, however, the mammalian remains of this period belong to what are considered the lower classes-themonotremata and marsupialia.

From reptiles we advance to birds, and thence to mammalia, which are commenced by marsupialia, acknowledgedly low forms in their class.