Source : Webster's Revised Unabridged Dictionary (1913)

Progne \Prog"ne\, n. [L., a swallow, traditionally said to be
   fr. Progne (The sister of Philomela), who was changed into a
   swallow, Gr. ?.] (Zo["o]l.)
   (a) A swallow.
   (b) A genus of swallows including the purple martin. See
       {Martin}.
   (c) An American butterfly ({Polygonia, or Vanessa, Progne}).
       It is orange and black above, grayish beneath, with an
       L-shaped silver mark on the hind wings. Called also {gray
       comma}.