86 
Thomas C. Barr, Jr. 
declivous. Last abdominal sternite of males with apical margin entire. 
Aedeagus scarcely arcuate, basal bulb not conspicuously enlarged nor 
deflexed, apex gradually attenuate and bluntly rounded at tip, only feebly 
produced; transfer apparatus with rather heavily sclerotized right piece, 
medially concave, apex knobbed or not, and broadly triangular, mem- 
branous, spiny left piece with apex spatulate and twisted 90°, or right 
piece as described and left piece absent; parameres moderately slender, 
bearing 4 long setae at their apexes. Type species: P. simplex , new species. 
Discussion.— This group consists of only two known species that occur 
in caves of Jackson and Clay counties, Tennessee, at the northeast edge 
of the Central Basin, in Ordovician limestones of the upper Cumberland 
River drainage, on the south (left) side of the river. The somewhat 
isolated troglobitic crayfish species Orconectes incomptus (Hobbs and 
Barr 1972) also occurs in caves of this region. 
The form of the copulatory sclerites and the serrulate humeri suggest 
a close relationship with the pubescens group (see Barr 1979); very faint 
pruinose microsculpture on the elytra of one species is additional 
evidence favoring this view. Different features, however, require the es- 
tablishment of a distinct group: depressed, robust form; more posterior 
position of the anterior discal puncture (pleomorphic); reduced 
pubescense and reduced pruinose microsculpture (probably apo- 
morphic); and the general form of the aedeagus. The transfer apparatus 
in simplex itself is similar in basic pattern to that of the pubescens group. 
One can speculate that the simplex group may be a link between the 
pubescens and menetriesi groups on the one hand and the numerous, 
small to medium species of the cumberlandus group on the other. In the 
cumberlandus group there is a single copulatory piece, presumably the left 
one; its simple structure, together with the apparent loss of the right 
piece, deprive the phylogenist of a key character in inferring relationships 
of the group to other Pseudanophthalmus species groups. The left 
copulatory piece in simplex is close enough to the cumberlandus transfer 
apparatus that a relationship is at least feasible. Habitus and geographic 
distribution of the simplex group, although weaker evidence supporting a 
relationship to the cumberlandus group, are at least consonant with an 
hypothesis that the two groups are phylogenetically close. 
Pseudanophthalmus simplex, new species 
Figs. 1, 2 
Etymology.— Latin simplex, “simple.” 
Diagnosis.— With the characters of the group as defined above; two 
copulatory pieces present; elytral striae deeper, impunctate; elytral 
microsculpture with a few pruinose patches near center of disc, which is 
moderately pubescent; apical groove longer. 
