[Kingdom] Animalia Linnaeus, 1758 - animals Grade Enterozoa Grade Cœlomata Phylum Echinoderma Branch Ambulacrata Class Echinoidea (Leske, 1778) - sea urchins and sand dollars Grade Palæechini Order Melonitidæ Genus Melonites Norwood & Owen, 1846, nom. illeg.