The Collaborative International Dictionary of English v.0.48:

Progne \Prog"ne\ (pr[o^]g"n[-e]), n. [L., a swallow,
   traditionally said to be fr. Progne (The sister of
   Philomela), who was changed into a swallow, Gr. Pro`knh.]
   (Zool.)
   (a) A swallow.
   (b) A genus of swallows including the purple martin. See
       Martin.
   (c) An American butterfly (Polygonia Progne syn. Vanessa
       Progne). It is orange and black above, grayish beneath,
       with an L-shaped silver mark on the hind wings. Called
       also gray comma.
       [1913 Webster]