Marsupialia

3 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Marsupialia \Mar*su`pi*a"li*a\
     (m[aum]r*s[=u]`p[i^]*[=a]"l[i^]*[.a]), prop. n. pl. [NL., fr.
     L. marsupium a pouch, bag, purse, Gr. marsy`pion, dim. of
     ma`rsypos, ma`rsipos.] (Zool.)
     A subclass of Mammalia, including nearly all the mammals of
     Australia and the adjacent islands, together with the


     opossums of America. They differ from ordinary mammals in
     having the corpus callosum very small, in being implacental,
     and in having their young born while very immature. The
     female generally carries the young for some time after birth
     in an external pouch, or marsupium. Called also {Marsupiata}.
     [1913 Webster] marsupialian

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Mammalia \Mam*ma"li*a\, n. pl. [NL., from L. mammalis. See
     {Mammal}.] (Zool.)
     The highest class of Vertebrata. The young are nourished for
     a time by milk, or an analogous fluid, secreted by the
     mammary glands of the mother.
     [1913 Webster]
  
     Note: Mammalia are divided into three subclasses; 
           [1913 Webster] I. {Placentalia}. This subclass embraces
           all the higher orders, including man. In these the
           fetus is attached to the uterus by a placenta.
           [1913 Webster] II. {Marsupialia}. In these no placenta
           is formed, and the young, which are born at an early
           state of development, are carried for a time attached
           to the teats, and usually protected by a marsupial
           pouch. The opossum, kangaroo, wombat, and koala are
           examples.
           [1913 Webster] III. {Monotremata}. In this group, which
           includes the genera {Echidna} and {Ornithorhynchus},
           the female lays large eggs resembling those of a bird
           or lizard, and the young, which are hatched like those
           of birds, are nourished by a watery secretion from the
           imperfectly developed mammae.
           [1913 Webster]

From WordNet (r) 2.0 [wn]:

  Marsupialia
       n : coextensive with the subclass Metatheria [syn: {order
           Marsupialia}]