92 
Thomas C. Barr, Jr. 
pusio group 
Same as pusio group of Valentine (1932), Jeannel (1949), and Barr 
(1965), readily identified by the elongate, cylindrical median lobe of the 
aedeagus. I differ with Jeannel (1949) in including P. higginbothami 
Valentine (WV) in the pusio group and placing P. fuscus in the grandis 
group. 
gracilis group (new group) 
Small species in which the males have an apical emargination in the 
last abdominal sternite; aedeagus long and slender, copulatory pieces 
subequal and rather short. The group is closely related to the inexpecta- 
tus group of central Kentucky (Krekeler 1973). 
gracilis Valentine 1931:253 (VA) 
hadenoecus Barr 1965:53 (WV) 
petrunkevitchi group (new group) 
Small species with a distinct, circular eye rudiment (as opposed to 
irregular, lunate scars in P. vicarius and some species of the grandis 
group); aedeagal apex slender and produced, transfer apparatus of two 
elongate pieces fused into a cylinder at the base of the internal sac. 
petrunkevitchi Valentine 1945:652 (VA) 
hoffmani Barr 1965:58 (VA) 
hortulanus Barr 1965:60 (VA) 
Four of these species groups {grandis, hubbardi, pusio, gracilis) have 
species in karst islands in the eastern part of the Allegheny Plateau as well 
as in the Appalachian valley proper. These distributions are consonant 
with the hypothesis that they are relics of ancient lineages which were 
edaphobitic in a Pleistocene (or earlier?) refugium within the Allegheny 
Plateau. In the grandis group, P. sylvaticus remains an edaphobite living 
in the forest floor of mountains above the Greenbrier valley caves where 
P. fuscus, its closest known relative, occurs. 
The petrunkevitchi group includes species at the eastern edge of the 
Appalachian valley and no species are known from the Allegheny karst 
islands. Although this group could have dispersed eastward from an 
Allegheny source, a Blue Ridge refugium is equally likely, or perhaps 
more likely in view of distribution of its known component species. 
ACKNOWLEDGMENTS. — Many persons have contributed spec- 
imens, given advice, or assisted me in the field over the years, and this 
paper would not have been possible without their help. I single out for 
