A NEW SPECIES OF ANARTIOCYSTIS (CALLOCYSTITIDA, GLYPTOCYSTITIDA) FROM THE BRASSFIELD FORMATION OF CENTRAL KENTUCKY

The Echinoderm fauna of the Brassfield Formation (Lower Silurian, Early to Middle Llandoverian) contains more than 30 species and is locally common in southern Ohio making it one of the most important Early Silurian faunas known (Foerste, 1919, 1936; Ausich, 1984a, 1984b, 1985, 1986a, 1986b, 1986c, 1987; Ausich and Schumacher, 1984; Ausich and Dravage, 1988). At present, the Brassfield Formation has produced two callocystitid rhombiferans including Brockocystis nodosarius Foerste (1919) and Anartiocystis foerstei Ausich and Schumacker (1984). Neither of these taxa is well-known, being described from a handful of moderately well to poorly preserved specimens each. The discovery of Anartiocystis whitei n. sp., the third callocystitid species known from the Brassfield Formation and second known species of the genus, greatly clarifies the morphology of the genus adding significant information on the plating of the ambulacra and stem.