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John R. Holsinger and David C. Culver 
the study area do not show the same high degrees of restriction to 
isolated, continuous belts of limestone as do those of beetles and 
pseudoscorpions. Populations of many of these species are found in 
caves developed in discontinuous exposures of limestone physically 
separated by clastic rocks. Assuming, however, that some gene exchange 
takes place between cave populations of the same species in different 
karst areas, then limited dispersal through areas composed of non- 
calcareous rock must occur. 
Recent discoveries of troglobites in non-calcareous caves and 
artificial mine adits in Japan by Ueno (1977) and in shallow underground 
compartments in Europe by Juberthie and Delay (1981) indicate how 
subterranean dispersal may occur outside caves per se. Ueno found 
troglobitic beetles, isopods, millipeds, and spiders in natural cavities and 
artificial mines excavated in fissured, non-calcareous rocks in Japan. In 
the Alps, Pyrenees, and Carpathians, Juberthie and his colleagues 
discovered troglobitic beetles, millipeds, isopods, and spiders in a distinct 
habitat type they named the shallow underground compartment (S.U.C.). 
Most of these species had been recorded previously from nearby caves. 
According to Juberthie and Delay (1981), the S.U.C. exists under the 
last layer of soil in mountainous areas and consists of cracks and 
fissures in the mantle rock. These cracks and fissures are in turn 
connected to caves and/or deep cracks that represent the deep 
underground compartment. In non-limestone areas, the S.U.C. was 
usually identified in schists; in limestone areas it was commonly 
associated with screes or talus. 
The observations by Ueno (1977) and Juberthie and Delay (1981) 
are good evidence that many troglobites inhabit shallow fissures and 
crevices near the surface in non-cavernous areas. Although not yet 
specifically identified, similar conditions probably exist in the Appala- 
chians. We do have good evidence, however, that some terrestrial 
troglobites in the study area occur outside caves and are therefore able 
to move between caves situated in different exposures of limestone. 
Both spiders ( Nesticus tennesseensis ) and collembolans {Pseudo sinella 
hirsuta and Sinella hoffmani ) have been collected from deep ground- 
litter habitats in forested areas on mountainsides outside limestone 
terranes (Barr 1967c, Christiansen and Bellinger 1980c, Gertsch 1984, 
and elsewhere this paper). It will not be surprising if other troglobitic 
species are eventually found in similar habitats, either in deep ground 
litter or under conditions analogous to those described by Ueno (1977) 
and Juberthie and Delay (1981). 
Of the three troglobitic trichoniscid isopods in the Virginia-east 
Tennessee area, Miktoniscus racovitzai is fairly widely distributed, 
whereas Amerigoniscus henroti and A. paynei have relatively limited 
ranges. The range of A. henroti is restricted to caves in a continuous 
