Paleechinoidea \Pa`le*["e]ch`i*noi"de*a\, n. pl. [NL. See
{Paleo-}, and {Echinoidea}.] (Zool.)
An extinct order of sea urchins found in the Paleozoic rocks.
They had more than twenty vertical rows of plates. Called
also {Palaeechini}. [Written also {Palaeechinoidea}.]
[1913 Webster]