This animal, fully named above, is the largest of the carnivorous marsupials of Australia, and the female possesses an abdominal pouch in which she carries her young, like a kangaroo. It is now found only in Tasmania, and it dwells amongst rocks, in rugged and mountainous regions. Because of its depredations upon the sheep herds, the Thylacine has been diligently hunted and destroyed, and now living specimens rarely are taken. In the zoological gardens of Europe and America, this species usually is kept in heated buildings, but it has been ascertained by experiment that this specimen thrives best in the open air. Living examples in captivity are now so very rare it is a difficult matter to keep one constantly on exhibition. THE OTTER POOLS, No. 31. The American Otter, (_Lutra canadensis_), is unfortunate in being the bearer of valuable fur; and in the northern regions, where the cold causes the development of fur that is available for the use of the furrier, this creature is so nearly extinct that trappers no longer pursue it. In the southern States, where its fur is short, rather coarse and “off color,” the Otter still is found. In some portions of eastern Florida, and along the coast of South Carolina, it is frequently taken. In captivity, it often becomes quite tame, even affectionate, and always is interesting. Unless closely confined, however, it is prone to wander, and meet premature death. In captivity the Otter usually is active and restless, and very much in evidence. Owing to the strength of its jaws, its ability to climb under certain conditions and its restless activity, it is difficult to confine a full-grown Otter in anything else than a complete box of iron cage-work. Few persons save woodsmen and naturalists are aware of the fact that in a wild state the Otter is a very playful animal, and is as fond of sliding down hill, over a wet and muddy slide, with a water plunge at the bottom, as any young person is of “shooting the chutes.” Like the small boy with the sled and a snowy hillside, the Otter sometimes indulges in its sliding pastime for an hour at a time, with a keen relish for the sport that is quite evident to all who have ever watched it. The Otter is a carnivorous animal, and in a wild state lives upon fish, frogs, crabs, young birds, small mammals, and, in fact, about any living thing which it can catch. The Coypu Rat, (_Myopotamus coypu_), of Central and South America, is interesting because of the fact that it is the largest of all rats or rat-like animals. In its habits it is as fond of water as the musk-rat. It is sufficiently clothed with fur to endure outdoor life in the Park, even in winter, and it has been acclimatized here in one of the other pools. It breeds persistently, and thrives in captivity, provided it is treated as it should be. THE SMALL-MAMMAL HOUSE, No. 35.