Source : Webster's Revised Unabridged Dictionary (1913)

Notobranchiata \No`to*bran`chi*a*ta\, n. pl. [NL. See {Notum},
   and {Branchia}.] (Zo["o]l.)
   (a) A division of nudibranchiate mollusks having gills upon
       the back.
   (b) The Dorsibranchiata.