The Collaborative International Dictionary of English v.0.48:

Mythologue \Myth"o*logue\, n. [See Mythology.]
   A fabulous narrative; a myth. [R.]
   [1913 Webster]

         May we not . . . consider his history of the fall as an
         excellent mythologue, to account for the origin of
         human evil?                              --Geddes.
   [1913 Webster]