The Collaborative International Dictionary of English v.0.48:

Ophidion \O*phid"i*on\, n.; pl. Ophidia. [L., fr. Gr. ? little
   snake, fr. 'o`fis a serpent.] (Zool.)
   The typical genus of ophidioid fishes. [Written also
   Ophidium.] See Illust. under Ophidioid.
   [1913 Webster]