82 
Psyche 
[June 
At any rate the maxillary and labial palpi were conspicu- 
ous and generalized in structure. Another interesting 
feature of the early psocids was their wings. In existing 
species the hind pair are much smaller than the fore, with 
a reduced venation, but in the Lower Permian species the 
fore and hind wings were alike. Some of the Upper Per- 
mian members show the beginnings of hind wing reduc- 
tion. Presumably these small creatures had essentially 
the same habits as many modern species, living under 
Figure 7. Dichentomum tinctum Tillyard (Order Corrodentia), from the 
Lower Permian of Kansas. Original restoration, based upon specimens in 
the Museum of Comparative Zoology. 
bark of trees or in leaf mould — hut the trees and leaves 
were very different from those now inhabited by their 
descendants. 
All the true bugs, i.e., Hemiptera, of the Permian were 
members of the suborder Homoptera. Most of them were 
small, with a wing expanse of less than an inch, though in 
a few this reached two inches. The Lower Permian spe- 
cies were much less specialized than the Upper Permian 
ones, but they had the characteristic beak and maxillary 
and mandibular bristles of existing bugs. The wings are 
interesting because they were about equal in size, and 
because the hind wing had the venational features of 
