Culex \Cu"lex\, n. [L., a gnat.] (Zool.)
   A genus of
         mosquitoes of the family Culicidae, to which
  
         most of the North American species belong. Some members of

           this genus are exceedingly annoying, as {Culex
         sollicitans},
   which breeds in enormous numbers in the
         salt marshes of the
   Atlantic coast, and Culex pipiens,
         the common house
   mosquito, breeding very widely in the
         fresh waters of North
   America. (For characters
         distinguishing these from the
   malaria mosquitoes, see
         Anopheles, above). The
         yellow-fever
   mosquito is now
         placed in another genus, Stegomyia.

   Note:
         This genus
         formerly (ca. 1900) included the gnat as
         well as the mosquito.
         [Webster 1913 Suppl. +PJC]