The Collaborative International Dictionary of English v.0.48:

Polypteroidei \Po*lyp`te*roi"de*i\, n. pl. [NL. See
   Polypterus, and -oid.] (Zool.)
   A suborder of existing ganoid fishes having numerous fins
   along the back. The bichir, or Polypterus, is the type. See
   Illust. under Crossopterygian.
   [1913 Webster]