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

Water snail \Wa"ter snail`\
   1. (Zo["o]l.) Any aquatic pulmonate gastropod belonging to
      {Planorbis}, {Limn[ae]a}, and allied genera; a pond snail.

   2. (Mech.) The Archimedean screw. [R.]