The Collaborative International Dictionary of English v.0.48:

Proteidea \Pro`te*id"e*a\, n. pl. [NL. See Proteus, and
   -oid.] (Zool.)
   An order of aquatic amphibians having prominent external
   gills and four legs. It includes Proteus and Menobranchus
   (Necturus). Called also Proteoidea, and Proteida.
   [1913 Webster]