Source : Webster's Revised Unabridged Dictionary (1913)

Paleechinoidea \Pa`le*["e]ch`i*noi"de*a\, n. pl. [NL. See
   {Paleo-}, and {Echinoidea}.] (Zo["o]l.)
   An extinct order of sea urchins found in the Paleozoic rocks.
   They had more than twenty vertical rows of plates. Called
   also {Pal[ae]echini}. [Written also {Pal[ae]echinoidea}.]