Two asellid isopods were described from Nickajack Cave, Tennessee: Caecidotea nickajackensis Packard (in Cope & Packard 1881) and Caecidotea richardsonae Hay (1901). It was long assumed that only one species was actually present in the cave, but Packard's type specimens were lost and the inundation of the cave by a Tennessee Valley Authority impoundment in 1967 eliminated the possibility of collecting additional specimens. Further confusion was created when specimens from Metcalf, Georgia were erroneously identified by Richardson as C. nickajackensis, then redescribed as that species by Steeves (1964). Examination of Hay's type specimens as well as a 1967 collection from Nickajack Cave now confirms the presence of two taxa. The name Caecidotea nickajackensis is applied to the Nickajack Cave asellid represented in the 1967 collection, whereas Caecidotea richardsonae is applied to the species represented in Hay's collection. Caecidotea catachaetus (Fleming & Steeves) is considered a junior synonym of C. richardsonae. Caecidotea putea, n. sp., is proposed as a valid name for the asellid from Metcalf, Georgia described by Steeves (1964).