130 
Psyche 
[June 
13a. Dorsal surface of segments coarsely granular or with irregular 
large tubercles; lateral shoulders prominent on midbody seg- 
ments (Figs. 10, 11, 13) 
Family Cleidogonidae, Pseudotremia . 
13b. Dorsal surface smooth between the seta-bearing knobs 14. 
14a. Pigmented specimens from Idaho caves, with more than 10 
ocelli Family Idagonidae, Idagona. 
14b. If from caves in Idaho, then not pigmented and with less than 
10 ocelli; if pigmented, then from other localities 15. 
15a. Ocelli in a triangular patch or two subparallel rows; adults 
usually longer than 12 mm; antennae long, reaching posteriad 
to the sixth or seventh segment (Fig. 8) 
Family Conotylidae. 
15b. Ocelli in a crescent-shaped or right-angled row, or completely 
absent; adults usually less than 9 mm long; antennae short, 
reaching posteriad to third segment 
Family Trichopetalidae, 18. 
1 6a. Body pigmented; to 20 mm long S triaria 
1 6b. Body white except for ocelli; to 30 mm (Fig. 12) 
Speostriaria 
17a. Without ocelli Speoseya 
17b. With 12-14 ocelli Opiona 
1 8a.. Twenty-eight segments; with ocelli Trichopetalum 
1 8b. Thirty segments; no ocelli 19 
19a. Segmental setae nearly as long as segments are wide; Missouri, 
Illinois, Kentucky, Tennessee, Alabama, Georgia (Fig. 7) .... 
Scoterpes. 
19b. Segmental setae little more than one-half as long as segments 
are wide; Virginia, West Virginia; eastern Kentucky (Fig. 6) 
Zygonopus. 
20a. Sixty to 80 segments (Fig. 13) Zoster act is. 
20b. Thirty-five to 45 segments Ameractis. 
Notes on Genera 
ORDER POLYDESMIDA 
None of the members of this order have ocelli, and if they undergo 
several molts in a cave, they may also become depigmented. How- 
ever, except for Ectopodesmus , all known true troglobites in this 
order are no more than 20 mm long. All troglobitic polydesmids 
known to me are also narrower than surface forms; the width of 
Ectopodesmus is only about 1/10 its length. The large, heavily pig- 
mented members of the families Polydesmidae and Xystodesmidae 
