Invertebrate Cave Fauna 
139 
With the exception of P. nelsoni, for which there is an apparent 
identity problem (see Barr 1965:45), the ranges of all species of 
Pseudanophthalmus in the study area are restricted to continuous 
exposures of cavernous limestone. As already pointed out, most of the 
species are known from single caves or small clusters of caves, although 
a few, like P. delicatus, P. gracilis , P. hoffmani, and P. rotundatus, have 
significantly larger ranges. Closely delimited ranges that coincide with 
continuous exposures of limestone strongly suggest that the dispersal of 
these beetles is limited to caves, solution channels, and other openings 
in carbonate bedrock. The two troglobitic pselaphid beetles from the 
study area also have highly restricted ranges, and each is known only 
from a single cave. These species were probably derived directly from 
edaphobitic ancestors in relatively recent times. Epigean congeners live 
in damp, deciduous-forest floors or in deep soil; in the genus Arianops, 
both epigean and hypogean species are eyeless (see Park 1960, 1965; 
Barr 1974). 
Troglobitic pseudoscorpions, like troglobitic trechine and pselaphid 
beetles, also have narrowly circumscribed ranges, and most are known 
only from single cave localities. Subterranean dispersal is apparently 
highly restricted and limited to continuous belts of cavernous limestone. 
Chamberlin and Malcolm (1960) concluded that the pseudoscorpion 
cave fauna is derived from epigean (endogean) forms in the same 
general geographic area. The highly localized distribution of the 
cavernicolous species tends to support their conclusion. 
Muchmore (1981) has pointed out that all of the troglobitic species 
of Kleptochthonius (29 described species in the subgenus Chamberlin- 
ochthonius) are restricted to the southeastern cave region in Kentucky, 
Tennessee, Virginia, West Virginia, and southern Indiana, and that 
troglobitic species in other chthoniid genera (viz., Apochthonius and 
Mundochthonius in the study area) occur on the periphery of the range 
of cavernicolous Kleptochthonius with little or no overlap. This suggests 
the possibility of competitive exclusion of other cavernicolous pseudo- 
scorpions by the strongly troglomorphic species of Kleptochthonius. 
The range of Kleptochthonius ( Chamber lino chthonius ), like that of 
Pseudanophthalmus , forms a trans-Appalachian distributional track, 
extending from the Interior Low Plateaus on the west to the Appalachian 
Valley and Ridge on the east. By comparison, troglobitic species of 
Apochthonius and Microcreagris are very widely scattered (Muchmore 
1981), but troglobitic Chitrella and Mundochthonius are rare and 
represented by only a few species (Malcolm and Chamberlin 1960, 
Muchmore 1973, Benedict and Malcolm 1974). 
With few exceptions, the ranges of other troglobitic arthropods 
(e.g., isopods, mites, spiders, millipeds, collembolans, and diplurans) in 
