Psyche 
[June 
170 
these beetles would have become progressively restricted to sinkholes, 
cave entrances, deep ravines, and to higher forests where the climate 
remains cool and moist in summer. As regional climate became still 
warmer, they could have survived at lower altitudes only in caves, 
becoming troglobites (obligate cavernicoles) or at higher altitudes, 
becoming edaphobites in humus and the upper layers of the soil. In 
either case, ecological mobility would be greatly reduced, with con- 
comitant restriction of gene flow, and many local endemics would 
have evolved. 
In most parts of eastern United States the regional climate has 
apparently become too warm for continued survival of edaphic 
trechines. Unlike Europe, there are few high areas in eastern United 
States near the margins of Pleistocene glaciation to serve as refugia 
for cryophilic insects. In eastern West Virginia the combination of 
extensive cavern development in the Greenbrier valley and the ex- 
istence of mountainous areas IOOO to 1400 meters high has preserved 
the edaphic, as well as the spelean remnants of the periglacial trechine 
fauna. 
The occurrence of P. sylvaticus under rocks embedded in stream 
gravels is particularly interesting, since many similar small streams of 
the Greenbrier basin plunge from sandstone mountains into the lime- 
stone valley below and disappear into caves or sinkholes. Some species 
of Pseudanophthalmus are commonly found in nearly identical mi- 
crohabitats along subterranean streams in caves. The logical sequence 
of events in cave colonization is thus obvious, at least in the Green- 
brier valley. The eventual discovery of one or more American 
Pseudanophthalmus spp. which exist equally well in both the soil 
and in caves would not be surprising. 
Cave colonization by trechines in eastern United States — particu- 
larly in areas adjacent to high, forested mountains and plateaus — 
may be somewhat more recent than commonly supposed. Much eye 
and pigment reduction may have taken place during adaptation to 
life in the soil of cool, moist forests. Eyespots are still present in 
P. grandis Val. (Greenbrier valley), in undescribed subspecies of 
P. fuscus Val. (Greenbrier valley), and in the species of the petrunke- 
vitchi group of Pseudanophthalmus (Appalachian valley of Virginia; 
petrunkevitchi Val., hoffmani Barr, hortulanus Barr, vicarius Barr). 
It seems reasonable to suppose that the presence of these rudiments 
indicates more recent eye reduction than in completely eyeless species 
(all others in the genus). All of these species with eye rudiments 
