ABSTRACTTwenty-three caves in West Virginia were investigated for the presence of dictyostelid cellular slime molds. Nine species were recovered, but only three of these (Dictyostelium sphaerocephalum, D. mucoroides, andD. rosarium) were recorded from at least 10 different caves. In general, the distribution of cellular slime molds in caves appears to be rather patchy, but in the microsites where they do occur, these organisms exhibit surprisingly high levels of abundance and diversity. The presence ofD. rosariumin West Virginia caves was unexpected, since this species has not yet been recorded from aboveground sites in the state. Previous reports of the occurrence and distribution ofD. rosariumindicate that the species is most commonly associated with moderately dry or saline soils in arid habitats. However, the results of the present study suggest thatD. rosariumis also able to exploit cave habitats to a greater extent than most other cellular slime mold species.