River crab

River \Riv"er\, n. [F. riv[`e]re a river, LL. riparia river,
   bank of a river, fr. L. riparius belonging to a bank or
   shore, fr. ripa a bank or shore; of uncertain origin. Cf.
   {Arrive}, {Riparian}.]
   1. A large stream of water flowing in a bed or channel and
      emptying into the ocean, a sea, a lake, or another stream;
      a stream larger than a rivulet or brook.
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            Transparent and sparkling rivers, from which it is
            delightful to drink as they flow.     --Macaulay.
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   2. Fig.: A large stream; copious flow; abundance; as, rivers
      of blood; rivers of oil.
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   {River chub} (Zool.), the hornyhead and allied species of
      fresh-water fishes.

   {River crab} (Zool.), any species of fresh-water crabs of the
      genus {Thelphusa}, as {Thelphusa depressa} of Southern
      Europe.

   {River dragon}, a crocodile; -- applied by Milton to the king
      of Egypt.

   {River driver}, a lumberman who drives or conducts logs down
      rivers. --Bartlett.

   {River duck} (Zool.), any species of duck belonging to
      {Anas}, {Spatula}, and allied genera, in which the hind
      toe is destitute of a membranous lobe, as in the mallard
      and pintail; -- opposed to sea duck.

   {River god}, a deity supposed to preside over a river as its
      tutelary divinity.

   {River herring} (Zool.), an alewife.

   {River hog}. (Zool.)
      (a) Any species of African wild hogs of the genus
          {Potamoch[oe]rus}. They frequent wet places along the
          rivers.
      (b) The capybara.

   {River horse} (Zool.), the hippopotamus.

   {River jack} (Zool.), an African puff adder ({Clotho
      nasicornis}) having a spine on the nose.

   {River limpet} (Zool.), a fresh-water, air-breathing mollusk
      of the genus {Ancylus}, having a limpet-shaped shell.

   {River pirate} (Zool.), the pike.

   {River snail} (Zool.), any species of fresh-water gastropods
      of {Paludina}, {Melontho}, and allied genera. See {Pond
      snail}, under {Pond}.

   {River tortoise} (Zool.), any one of numerous fresh-water
      tortoises inhabiting rivers, especially those of the genus
      {Trionyx} and allied genera. See {Trionyx}.
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