Abstract
A new classification is proposed for late Paleozoic Edrioasteroidea (Echinodermata), separating forms with the advanced clavate thecal design from those with the ancestral pyrgate thecal design, and a new Subfamily Discocystinae is erected to receive the clavate agelacrinitid edrioasteroids. Lepidodiscus Meek and Worthen is restricted to the pyrgate type species L. squamosus (Meek and Worthen) and two unnamed species, whereas the clavate L. laudoni (Bassler) is assigned to Clavidiscus, new genus. The clavate Discocystis priesti Strimple and three new species, Hypsiclavus kinsleyi, new genus and species, Hypsiclavus huntsvillensis, new genus and species, and Hypsiclavus guensburgi, new genus and species, are placed in Hypsiclavus, new genus. Bostryclavus, new genus, is erected to receive Echinodiscus sampsoni Miller. A redescription of Discocystis kaskaskiensis (Hall) and a diagnosis of Spiraclavus Sumrall are included for completeness.