The Collaborative International Dictionary of English v.0.48:

Paleichthyes \Pa`le*ich"thy*es\, n. pl. [NL. See Paleo-, and
   Ichthyology.] (Zool.)
   A comprehensive division of fishes which includes the
   elasmobranchs and ganoids. [Written also Pal[ae]ichthyes.]
   [1913 Webster]