DIDELPHIS, the opossum, in natural history, a genus of Mammalia of the or der Fern. Generic character : fore-teeth small and rounded ; upper, ten, small and rounded ; intermediate, two, longer ; lower, eight, intermediate two broader, and very short ; tusks long ; grinders clenticulated ; tongue fringed with papil lx ; abdominal pouch, in most species, containing the teats.
These animals first became known to Europeans on the discovery of America, and excited their particular attention by a deviation in eir structure from that of all other known quadrupeds. This sin gularity consists in the female's posses sion of a bag or pouch in the loWer part of the abdomen, which is opened and closed at pleasure, and to which her young resort for shelter and security in a variety of dangers. Some females pos sess, according to Gmelin, two or three of these pouches, and the male is stated also, in the same author, occasionally to have one. These animals live in the woods, burrowing in the earth, and, by means of a prehensile tail, are alert in climbing trees. Their general motion is slow, and their food consists of insects, worms, and vegetables, young birds, and particularly poultry. They are by no means peculiar to the Western continent, but are to be found in various other parts of the world. According to both Shaw and Gmelin, there are twenty-one spe cies, of which the following are most de serving of attention : for the spotted opossum, see Mammalia, Plate IX. fig. 1.
D. virginiana, the Virginian opossum. The size of this animal is little inferor to that of the domestic cat ; its tail is cover ed with a scaly skin, the divisions of which give it the resemblance of a small snake, and the animal has the faculty of coiling it with great tenacity round any object, and of thus increasing its means of defence and attack, and its facility of movement among the branches of trees. The teats of the female are inclosed in that astonishing receptacle which dis tinguishes almost every species of this animal ; and immediately after their birth the young are introduced by their parent to that cavity, or resort to it from an impulse of their own. After first emerging from it, on attaining a certain degree of growth and vigour, they have repeated recourse to it on alarms of dan ger, and are securely kept, and even carried about in it, by the dam, till all ground of apprehension ceases. In some
species this cavity does not exist, and na ture has substituted for it a sort of fur row. The Virginian opossum is gentle and inoffensive in its manners, but has a rank smell. It is well known to almost every farmer, that this animal, when overtaken or captured by hunters, will feign itself dead, and may be carried a considerable distance with out exhibiting any appearance of life. The female produces four or five at a birth, and prepares a sort of nest for her self, of grass, near the root of a tree. She has the power of closing her pouch, and preserving it closed so completely, as to render it a matter 4 great difficulty to open it. D. marsupia is, the Amboyna .opossum, is found in the warmer climates of .South America, as well as in some countries of the East. It is bred with rabbits in India, and passes, indeed, un der the name of the Aroe rabbit. It is not only considered as fit for food, but regarded as a considerable delicacy. This species is much larger than the last. D. lemurina, or the New Holland bear. The length of this animal's body is about a foot and a half, and that of its tail about afoot. It is, perhaps, the most elegant species of the genus. In its manners, or mode of subsistence, it resembles the other species ; it is frequently perceived, however, to sit like a squirrel, with its body erect, and holding its food in its hands. Its fur is extremely rich, soft, and thick. D. petaurus, or the great fly trig opossum of New Holland, is nearly two feet in length to the beginning of its tail, which is nearly two feet more. By an expansile membrane reaching on each side of its body, from the fore to the hind legs, it is enabled to leap to an ex traordinary distance, and has thus gained the designation by which it is distinguish ed. Its fur is of the most exquisite fine ness, and for the greater part of a sable or deep-grey brown colour, extremely brilliant. See Mammalia, Plate IX. fig. 2. D. sciurea, or the squirrel opossum. This and the last species are considered by Shaw as the two most beautiful qua drupeds in New South Wales. Its gene ral appearance extremely resembles that of a squirrel. Its fur is, if possible, more soft and valuable than that of the flying opossum. Its abdominal pouch is rather beyond the usual proportion. This ani mal reposes by day, but during the night ranges in full activity.