1967] 
M ockford — - Electrentomoid Psocids 
159 
Group Amphientometae, and Suborder Psocomorpha. It is apparently 
universally absent in the Permian fossil psocids, which strongly sug- 
gests that its absence is the plesiomorphous condition for the order, 
and that it has arisen several times independently (at least twice) 
within the order. Its absence in the Nanopsocetae rules out the 
possibility that this group is phylogenetically subordinate to the 
Amphientometae. At the same time its absence in most members of 
the Suborder Trogiomorpha establishes the same thing for that group, 
with regard to their relationship to the Amphientometae and to the 
Suborder Psocomorpha. The Trogiomorpha also cannot be sub- 
ordinate to the Nanopsocetae, as they bear several plesiomorphous 
characters which the Nanopsocetae lack (M 3 present in forewing, 
Cu branched in hindwing. 
The Suborder Trogiomorpha and the Group Nanopsocetae, then, 
appear to be valid monophyletic lines not included in the Amphi- 
entometae. At the same time, possession of a nodulus shows the 
Amphientometae to be a monophyletic group and its possession of vein 
2A of the forewing shows it to be not included within either Trogio- 
morpha or Nanopsocetae. 
It is now necessary to try to decide whether Suborder Psocomorpha 
is phylogenetically coordinate with the Amphientometae or if a sub- 
ordinance relationship exists between them. On the basis of characters 
used above to establish monophyly of the Psocomorpha, the phylo- 
genetic subordinance of the Amphientometae to the Psocomorpha is 
ruled out. 
It must be noted that the Family Amphientomidae shares a number 
of characters with the Psocomorpha. These include tarsal ctenidio- 
bothria, lacinia with lateral cusp curved out and bearing short den- 
ticles, and the greatly enlarged postclypeus, which is longer than frons 
in anterior view of face. These characters have good probability of 
being shared through synapomorphy, hence marking a monophyletic 
line. 
Fig. 104. — Dendrogram showing probable phylogenetic relationships of 
major lines of Psocoptera and families and genera of Electren- 
tomoid psocids. Numbers refer to following notations: (1) 
nodulus acquired; (2) third valvula bilobed apically; (3) 
lateral cusp of lacinial tip curved outward, bearing low, rounded 
denticles; (4) third valvular lobes reunited, spines or denticles 
of first femur absent; (5) vein M of hindwing branched, com- 
pound eyes color-banded; (6) tarsal ctenidiobothria present. 
