136 
Psyche 
[June 
plateau have several species that are perhaps troglobitic; C. reddelli 
Causey is known from Culbertson, Wheeler, and Childress Counties, 
C. speobia (Chamberlin) from a long list of counties in central and 
southwest-central Texas (Causey^ 1964). 
ORDER CALLIPODIDA 
Hoffman and Lohmander (1964) use this name for the order 
usually called Lysiopetalida in this country. The family name of the 
North American genera is uncertain. 
Genus Tetracion Hoffman 
Map 2; Fig. 2 
Tetracion is represented by two species, T. jonesi Hoffman (Fig. 
2), in the Tennessee River drainage in northeastern Alabama, and 
T. tennesseensis Causey (1959a) in Warren and Grundy Counties, 
Tennessee, in the Cumberland River drainage. Hoffman (1956) 
described two subspecies of T. jonesi from widely separated caves. 
Since that time, large series of specimens collected by carrion baiting 
in caves from the intervening localities have come into the collections 
of the Museum of Comparative Zoology. I have studied this material 
in detail and have come to the conclusion that the distinction between 
T. j. jonesi and T. j. antraeum cannot be maintained, because of the 
indistinct gradation between the two type localities. Relatively few 
specimens of T. tennesseensis have been collected, but it seems distinct 
in range and in structure, being somewhat smaller than T. jonesi. 
ORDER CHORDEUMIDA 
According to Causey (1960b), fully 80% of the troglobitic milli- 
peds of North America fall in this order. Its members are easily 
distinguished from all others by the presence of six prominent ma- 
crosetae on each segment. 
Family Conotylidae Cook 
Map 3 ; Fig. 8 
Two genera with troglophilic members occur in the eastern United 
States. Conotyla has two species known primarily from caves, C. 
bollmani (McNeill) of Indiana (Fig. 8), and C. blakei (Verhoeff) 
of New York, Pennsylvania and Maryland. Austrotyla specus 
(Loomis) is a troglophile of Missouri, Illinois, and Iowa. Conotyla 
pectinata Causey, of northern Illinois, represents a third distinct 
troglophilic genus, and Conotyla humerosa Loomis, a fourth genus 
containing the only real troglobites of the family. The details of 
