barrier reefs

Coral \Cor"al\, n. [Of. coral, F, corail, L. corallum, coralium,
   fr. Gr. kora`llion.]
   1. (Zool.) The hard parts or skeleton of various Anthozoa,
      and of a few Hydrozoa. Similar structures are also formed
      by some Bryozoa.
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   Note: The large stony corals forming coral reefs belong to
         various genera of {Madreporaria}, and to the hydroid
         genus, {Millepora}. The red coral, used in jewelry, is
         the stony axis of the stem of a gorgonian ({Corallium
         rubrum}) found chiefly in the Mediterranean. The {fan
         corals}, {plume corals}, and {sea feathers} are species
         of {Gorgoniacea}, in which the axis is horny.
         Organ-pipe coral is formed by the genus {Tubipora}, an
         Alcyonarian, and {black coral} is in part the axis of
         species of the genus {Antipathes}. See {Anthozoa},
         {Madrepora}.
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   2. The ovaries of a cooked lobster; -- so called from their
      color.
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   3. A piece of coral, usually fitted with small bells and
      other appurtenances, used by children as a plaything.
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   {Brain coral}, or {Brain stone coral}. See under {Brain}.

   {Chain coral}. See under {Chain}.

   {Coral animal} (Zool.), one of the polyps by which corals are
      formed. They are often very erroneously called {coral
      insects}.

   {Coral fish}. See in the Vocabulary.

   {Coral reefs} (Phys. Geog.), reefs, often of great extent,
      made up chiefly of fragments of corals, coral sands, and
      the solid limestone resulting from their consolidation.
      They are classed as {fringing reefs}, when they border the
      land; {barrier reefs}, when separated from the shore by a
      broad belt of water; {atolls}, when they constitute
      separate islands, usually inclosing a lagoon. See {Atoll}.
      

   {Coral root} (Bot.), a genus ({Corallorhiza}) of orchideous
      plants, of a yellowish or brownish red color, parasitic on
      roots of other plants, and having curious jointed or
      knotted roots not unlike some kinds of coral. See Illust.
      under {Coralloid}.

   {Coral snake}. (Zo)
      (a) A small, venomous, Brazilian snake {(Elaps
          corallinus)}, coral-red, with black bands.
      (b) A small, harmless, South American snake ({Tortrix
          scytale}).

   {Coral tree} (Bot.), a tropical, leguminous plant, of several
      species, with showy, scarlet blossoms and coral-red seeds.
      The best known is {Erythrina Corallodendron}.

   {Coral wood}, a hard, red cabinet wood. --McElrath.
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