from The Century Dictionary.

  • noun A genus of acarids founded by Müller in 1781, at present restricted to those fresh-water mites in which the third joint of the palpi is the longest, the beak is as long as the palpi, and the mandibles have sharp blades.
  • noun A genus of water-beetles, of the family Dytiscidœ, containing such as the European H. tarda.


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