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[Vol. 93 
any, still occurring among the taxa, the relative degree of differenti- 
ation between the various taxa, and the manner in which the present 
geographic pattern has been produced may be strengthened by the 
availability of genetic data such as those obtained through gel elec- 
trophoresis (Barr, 1979b; Turanchik and Kane, 1979). 
As Barr (1979b) has indicated, the large geographic distribution 
and abundance of Neaphaenops tellkampfi populations present an 
excellent opportunity to assess the extent of gene flow between local 
populations of a troglobitic trechine using both morphological and 
electrophoretic data. Among the many species of troglobitic tre- 
chine carabid beetles in the United States, Neaphaenops tellkampfi 
is noteworthy for having the most extensive geographic range and 
being one of the most abundant species of the group (Barr, 1979b, 
1981). The species is distributed (Fig. 1) from just south of the Ohio 
River in the north to its southern limit near the Tennessee border, in 
the highly cavernous Mississippian limestones of the Pennyroyal 
Plateau in west central Kentucky (Barr, 1979b). The western extent 
of its range is delimited by the noncavernous Big Clifty sandstone, 
and the eastern and southeastern limits of the range correspond 
roughly with the contact with the Salem and Warsaw limestones 
(Barr, 1979b). 
Neaphaenops tellkampfi , like other cave trechines, is an impor- 
tant predator in terrestrial cave communities (Barr and Kuehne, 
1971; Kane and Poulson, 1976). Unlike other troglobitic trechines in 
the Pennyroyal Plateau, however, N. tellkampfi has evolved special- 
ized behaviors which allow it to prey on the eggs and early instar 
nymphs of the common cave “cricket” Hadenoecus subterraneus 
(Orthoptera: Rhaphidophoridae), resources which are energy rich 
and seasonally abundant (Kane and Poulson, 1976; Hubbell and 
Norton, 1978). This predator-prey interaction has evolved to the 
extent that no N. tellkampfi populations occur outside the range of 
H. subterraneus (Hubbell and Norton, 1978). In fact, Barr (1979b) 
has suggested that at least part of the eastern limits of the N. tell- 
kampfi range may be determined by the absence of H. subterraneus 
further east, rather than to the presence of any extrinsic geological 
barrier. 
Using morphological and geological criteria, Barr (1979b) has 
recognized four subspecies of N. tellkampfi. The nominate subspe- 
cies, N. t. tellkampfi, on which most of the ecological studies dis- 
