The same invertebrate fauna of 17 species was found in Devils Den Cave, Washington County, Arkansas, in 1969 and 1979. The fauna consists of 1 trogloxene, 14 troglophiles, and 2 troglobites, a spider, Porrhomma cavernicolum, and a collembolan, Pseudosinella dubia. Devils Den Cave has a well developed cavernicolous fauna, although it is in sandstone which generally supports a poor cave adapted fauna. The troglobites probably evolved in the vicinity of northwestern Arkansas in limestone caves or in deep forest soils of the Ozark region. They then dispersed overland, perhaps as recently as the late Wisconsinan, to occupy this sandstone cave