134 
Psyche 
[December 
The small setae covering the thorax and abdomen are 
not arranged in any readily visible pattern. There is a 
very rough arrangement into transverse rows, but this is 
neither constant nor very clear. The common situation is 
for these rows to be as follows: thoracic segment one, none; 
thoracic segment two, 6; thoracic segment three, 5 or 6; 
abdominal segment one, 4; abdominal segment two, 4; 
abdominal segment three, 4; abdominal segment four, 5; 
abdominal segment five, 5; abdominal segment six, 2. 
The first row of the fifth segment is usually preceded by 
a single discreet seta on either side. The length of the 
longer setae varies considerably, but those on the fifth and 
sixth segments are usually longer than those on the other 
segments. 
Relationships 
This species is the first of the genus to be described from 
North America. While fitting into the generic limits as 
already set up, it is readily distinguishable from all pre- 
viously described species. Of these it would appear to be 
most closely related to P. binoculatus Kseneman (1934), 
and to P. alticola Bagnall (1949). It can be distinguished 
from the former by the lack of eyes and sensory hairs on 
the fifth abdominal segment, as well as by the swollen 
nature of the P.A.O. It can be separated from the latter 
by the shorter, broader P.A.O. and the possession of long 
setae on the fifth and sixth abdominal segments. 
Measurements 
All segmental measurements and ratios are of the set- 
aceous area along the middorsal line, excluding the inter- 
segmental membranes. All measurements in millimeters. 
Holotype: total length, excluding antennae, .64; cephalic 
diagonal, .12 ; thoracic segment two, .05 ; thoracic segment 
three, .05 ; abdominal segment one, .04 ; abdominal segment 
two, .04; abdominal segment three, .04; abdominal seg- 
ment four, .05; abdominal segment five, .04; abdominal 
segment six, .01 ; antennal segment one, .01 ; antennal seg- 
ment two, .03 ; antennal segment three, .03 ; antennal seg- 
ment four, .04; fore unguis, .014; fore unguiculus, .007; 
hind unguis, .015; hind unguiculus, .008. 
