68 
John R. Holsinger and David C. Culver 
Probably the most common and widespread cavernicolous collem- 
bolan in the study area is Tomocerus bidentatus (Fig. 31 A), a lightly 
pigmented troglophile with small eyes that is also recorded from epigean 
and cave habitats in the eastern United States and from two caves in 
California (Christiansen 1964a, Christiansen and Bellinger 1980c). 
Tomocerus flavescens, also a troglophile (or trogloxene?), is recorded 
from caves in many parts of the United States (Christiansen 1964a, 
Christiansen and Bellinger 1980c), but it is much less common than T. 
bidentatus in the study area (Fig. 25). 
The second most significant family in the regional cave collembolan 
fauna is Sminthuridae, represented by six species in the genus 
Arrhopalites (Fig. 24). Most of these species are troglophiles and 
trogloxenes and are recorded from a large part of the United States (see 
Christiansen and Bellinger 1981). Arrhopalites clarus, however, is at 
present known only from caves and is apparently troglobitic despite its 
broad distribution, which includes localities in Arkansas, Missouri, 
Virginia, and West Virginia (see Christiansen 1982). The most common 
species of the genus in regional caves is A. pygmaeus, a troglophile 
uncommon in epigean habitats but recorded from caves throughout a 
large part of the southeastern and south-central United States 
(Christiansen 1964a, Christiansen and Bellinger 1981). Arrhopalites 
ferrugineus (Packard), reported earlier from caves in Virginia by 
Holsinger (1963a), is considered a synonym of this species by 
Christiansen (1966). 
In other families, Folsomia Candida (Isotomidae), a probable 
troglophile, is recorded from a few caves in Virginia as well as from 
caves over a wide area of the United States (Christiansen and Bellinger 
1980b). The families Hypogastruridae and Onychiuridae are represented 
in study-area caves by several trogloxene or accidental species, which, 
with the exception of Onychiurus ramosus, are based on single cave 
records. Onychiurus ramosus is recorded from several caves in Virginia 
and one in northeastern Utah (see Peck 1981a); otherwise it is widespread 
in epigean habitats over much of the United States (Christiansen and 
Bellinger 1980b). 
Family Entomobryidae 
Entomobrya socia Boren (TX or AC) 
Virginia. — Giles Co.: New River Cave. 
Pseudosinella aera Christiansen and Bellinger (TP or TX) 
Virginia. — Shenandoah Co.: “Cave” (Christiansen and Bellinger 
1980c:966). 
Comments. — Also recorded from caves in Illinois, Kentucky, 
Missouri, Tennessee, and Texas (Christiansen and Bellinger 
1980c). 
