With the exception of the Opossums, which are natives of America, the tribe is peculiar to New Holland and its appendages, and to some of the islands which form the great chain of connexion between that insular continent and South-eastern Asia. The former is, however, their head quarters, and the species which are found beyond its limits are few in number compared with those which people its territory, and, what is more remarkable, people it to the exclusion of nearly all the other Mammalia; the dog alone, the universal concomitant of man, and one or two species of rats, disputing with them their title to its exclusive possession; for those paradoxical creatures, the Ornithorhynchus and Echidna, if really mammiferous, approximate closely in structure to the Marsupial tribe. The largest of these animals are the Kanguroos, whose generic characters we shall now proceed to describe. Their teeth are only of two kinds, the canines being altogether wanting. The incisors are six in the upper jaw, and two only in the lower; the former short, and arranged in a curved line, and the latter long, pointed, closely applied to each other, and directed forwards. The molars are separated from the incisors by a considerable vacant space, and are five in number on each side of each jaw. The most remarkable peculiarity in the external form of these animals consists in the extreme disproportion of their limbs, the anterior legs being short and weak, while the posterior are extremely long and muscular. The tail too is excessively thick at its base, of considerable length, and gradually tapering; and this singular conformation enables it to act in some measure as a supplemental leg, when the animal assumes an erect or nearly erect posture, in which position he is supported as it were on a tripod by the joint action of these three powerful organs. By means of this combination they will, when flying from danger, take a succession of leaps of from twenty to thirty feet in length and six or eight in height; but even in their more quiet and gradual mode of progression they also make use of their tail in conjunction with their four extremities. The fore feet are furnished with five toes, each terminating in a moderately strong and arcuated claw. The hinder extremities, on the contrary, have only four toes, the two interior of which are united together so as to form the appearance of a single one furnished with two short and feeble claws; the third is long, of great strength, and terminated by a large and powerful claw having the form of a lengthened hoof; and the fourth, the most external of the series, is similar in character to the third, but of much smaller dimensions. The head and anterior part are small and delicate, and appear quite disproportioned to the robust posterior half of the body; and this disproportion is equally striking, whether the animal assumes an erect position or crouches forwards upon all fours. In either case the whole