perennibranchiata

from The Collaborative International Dictionary of English v.0.48

Perennibranchiata \Per*en`ni*bran`chi*a"ta\, n. pl. [NL. See
   {Perennial}, and {Branchia}.] (Zool.)
   Those Batrachia which retain their gills through life, as the
   menobranchus.
   [1913 Webster]