1969] 
Shear — Cave Millipeds 
127 
America; in the Trichopetalidae, Scoterpes (to 8 mm) is larger than 
Trichopetalum (4-5 mm). 
Troglobitic millipeds undoubtedly evolved under a combination of 
two major factors: their preadaptation for the cave habitat as a. 
part of the humus fauna, and the climatic fluctuations of the Quater- 
nary. This will be further discussed in a forthcoming revision of the 
Conotylidae. 
Zoogeographically, the troglobitic millipeds present an interesting 
picture. Pseudotremia, which I am currently revising in connection 
with a larger study of the family Cleidogonidae, has more than 40 
species in the Appalachian region from Alabama north to Indiana and 
northeast West Virginia. These fall into three groups: those which 
are clearly troglobitic, with, in some cases, a virtual absence of pig- 
ment and ocelli ; a group of troglophiles, lightly pigmented and with 
25-30 ocelli in each eyepatch; and a small number of very large 
epigean species with dark pigment and 35 or more ocelli in each 
eyepatch. The epigean species are mostly found at higher elevations, 
or associated with known glacial relict areas. The troglobites, for 
reasons not presently clear, are separated into two groups, one in an 
arc from extreme northwest Georgia and northeast Alabama through 
central Tennessee and Kentucky to Indiana, and a second enclave in 
western Virginia and eastern West Virginia. Endemism is remark- 
ably high ; two caves only a mile apart and in the same stream valley 
in DeKalb Co., Tennessee, have different species of Pseudotremia. 
In contrast to this pattern of a widespread genus with highly 
endemic species are two other kinds of situations. A single species, 
Cambala speohia , ranges over an area of 2500 square miles in the 
Edwards Plateau in Texas; Antriadesmus fragilis is known only from 
a single cave in a well-collected area. 
The ecological postion of cave millipeds is uncertain. Like all 
troglobites, they are ultimately dependent upon importation of food 
into the cave ecosystem from the outside. The most frequent ecologi- 
cal note with collections of troglobitic millipeds indicates that the 
specimens were found on rotting wood. I have examined the fore- 
guts of individuals of five species of Pseudotremia and found that 
wood tracheids were the only identifiable remains. I have also ob- 
served a West Virginia species of Pseudotremia feeding on paper, 
candle wax, raccoon feces and a dead salamander. Tetracion jonesi 
Hoffman can be baited with carrion; a related epigean genus, Aba- 
cion, is at least partly carnivorous. In turn, cave millipeds may serve 
as food for cave crickets and salamanders; I have seen Pseudotremia 
