资料来源 : pyDict

单孔目

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Monotremata \Mon`o*trem"a*ta\, n. pl. [NL., fr. Gr. ? single + ?
   hole.] (Zo["o]l.)
   A subclass of Mammalia, having a cloaca in which the ducts of
   the urinary, genital, and alimentary systems terminate, as in
   birds. The female lays eggs like a bird. See {Duck mole},
   under {Duck}, and {Echidna}.

Mammalia \Mam*ma"li*a\, n. pl. [NL., from L. mammalis. See
   {Mammal}.] (Zo["o]l.)
   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.

   Note: Mammalia are divided into three subclasses; -- I.
         {Placentalia}. This subclass embraces all the higher
         orders, including man. In these the fetus is attached
         to the uterus by a placenta. 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. 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
         mamm[ae].

资料来源 : WordNet®

Monotremata
     n : coextensive with the subclass Prototheria [syn: {order
         Monotremata}]