Classification of echinoids

Abstract

The classification proposed by J. W. Durham and R. V. Melville in 1957 (J. Paleont. v. 31, p. 242-272) is critically reviewed, and continued recognition of the subclasses Regularia and Irregularia is advocated. Three superorders of the Regularia and two superorders of the Irregularia are recognized in the classification here proposed.