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OPOSSUM
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OPOSSUM , an See also:American See also:Indian name properly belonging to the American marsupials (other than Caenolestes) , but in See also:Australia applied to the phalangers (see See also:PHALANGER). True opossums are found throughout the greater See also:part of See also:America from the See also:United States to See also:Patagonia, the number of See also:species being largest in the more tropical parts (see See also:MARSUPIALIA). They See also:form the See also:family Didelphyidae, distinguished from other marsupial families by the equally See also:developed See also:hind-toes, the nailless but fully opposable first hind-toe, and by the dentition, of which the See also:formula is i. -t, c. -, p. , m. -; See also:total 50. The peculiarity in the mode of See also:succession of these See also:teeth is explained in the See also:article referred to. Opossums are small animals, varying from the See also:size of a See also:mouse to that of a large See also:cat, with See also:long noses, ears and tails, the latter being as a See also:rule naked and prehensile, and with the first toe in the hind-See also:foot so fully opposable to the other digits as to constitute a functionally perfect posterior " See also:hand." These opposable first toes are without See also:nail or claw, but their tips are See also:expanded into broad See also:flat pads, which are of See also:great use to these climbing animals. On the anterior limbs all the five digits are provided with long See also:sharp claws, and the first toe is but little opposable. The numerous cheek-teeth are crowned with See also:minute sharply-pointed cusps, with which to crush the See also:insects on which these creatures feed, for the opossums seem to take in See also:South America the See also:place in the See also:economy of nature filled in other countries by hedgehogs, moles, shrews, &c. The true opossums are typically represented by Didelphys marsupialis, a species, with several See also:local races, ranging over the greater part of See also:North America (except the extreme north). It is of large size, and extremely See also:common, being even found living in towns, where it acts as a See also:scavenger by See also:night, retiring for shelter by See also:day upon the See also:roofs or into the sewers. It produces in the See also:spring from six to sixteen See also:young ones, which are placed by the See also:mother in her pouch immediately after See also:birth, and remain there until able to take care of themselves; the See also:period of gestation being from fourteen to seventeen days. A local See also:race found in Central and tropical South America is known as the crab-eating opossum (D. marsupialis cancrivora). The second sub-genus, or genus, Metachirus contains a considerable number of species found all over the tropical parts of the New See also:World. They are of See also:medium size, with See also:short, See also:close See also:fur, very long, scaly and naked tails, and have less developed ridges on their skulls. They have, as a rule, no pouch in which to carry their young, and the latter therefore commonly ride on their mother's back, holding on by winding their prehensile tails See also:round hers, as in the figure of the woolly opossum. The latter belongs to the sub-genus Philander, which is nearly allied to the last; its full See also:title being Didelphy(Philander) lanigera. The philander (D. [P:] philander) is closely related. The See also:fourth sub-genus (or genus) is Marmosa (Micoureus, or Grymaeomys), differing from the two last by the smaller size of its members and by certain slight See also:differences in the shape of their teeth. Its best-known species is the murine opossum (D. marina), no larger than a mouse, of a See also:bright-red See also:colour, found asfar north as central See also:Mexico, and extending thence to the south of See also:Brazil. A second well-known species is D. cinerea, which ranges from Central America to western Brazil, See also:Peru and See also:Bolivia. Yet another See also:group (Peramys) is represented by numerous See also:shrew-like species, of very small size, with short, hairy and non-prehensile tails, not See also:half the length of the See also:trunk, and unridged skulls. The most striking member of the group
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The Woolly Opossum (Didelphys lanigera) and young.
is the Three-striped Opossum (D. americana) from Brazil, which is of a reddish See also:grey colour, with three clearly-defined deep-See also:black bands down its back, as in some of the striped mice of See also:Africa. D. dimidiata, D. nudicaudata, D. domestica, D. unistriata and several other South American species belong to this group. Lastly we have the Chiloe See also:Island [opossum (D. gliroides), alone representing the sub-genus Dromiciops, which is most nearly allied to Marmosa, but differs from all other opossums by the short furry ears, thick hairy tail, doubly swollen auditory bulls, short canines and peculiarly formed and situated incisors.
Whatever difference of See also:opinion there may be as to the right of the above-mentioned See also:groups to generic separation from the typical Didelphys, there can be none as to the distinctness of the See also:water-opossum (Chironectes minimus), which differs from all the other members of the family by its fully webbed feet, and the dark-See also: 184, and later papers in the same and other serials. (R. Additional information and CommentsThere are no comments yet for this article.
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