Webster’s Revised Unabridged Dictionary · 1913
Paleëchinoidea
Pa′le·ëch′i·noi′de·a (pā′lē·ĕk′ĭ·noi′dē·ȧ), n. pl. [NL. See Paleo-, and Echinoidea.] (Zoöl.) An extinct order of sea urchins found in the Paleozoic rocks. They had more than twenty vertical rows of plates. Called also Palæechini. [Written also Palæechinoidea.]