368 
Psyche 
[December 
Cul and R at the base is really the free, short piece of the 
stem of M. This tendency for MA to coalesce with the 
radial sector, and MP to coalesce with Cul is found 
in nearly every order of insects where there is a marked 
reduction in the venation. Whether my conception of 
the changes in the structure of the media is correct or 
not, the fact remains that the convex vein just below Rs 
in the Protohymenoptera can only be MA, and the concave 
vein before Cul must be MP. The nature of the modifica- 
tions which resulted in the elimination of the two veins 
is perhaps not so obvious; but by merely carryng out 
the coalescence already suggested or begun in the Megase- 
coptera, we obtain conditions so strikingly similar to what 
we actually find in the Protohymenoptera that I believe 
the process outlined above is the correct one. 
So few are the specializations in the wings of the Proto- 
hymenoptera over those of the Megasecoptera that we have 
in this fact further proof of the very close affinity of these 
two orders. It is true that we postulated such a relationship 
at the beginning of our discussion of the wing venation in 
the Protohymenoptera; but the ease with which we can 
derive one type from the other is itself an indication of 
such an association. From all aspects, therefore — wing 
structure, body structure, and wing venation — the evidence 
points to the one conclusion. I am therefore led to agree 
with Handlirsch’s original suggestion, that these insects 
are not only allied to the Megasecoptera, but are actually 
members of that order. They undoubtedly constitute a 
distinct suborder (Protohymenoptera), as specialized Per- 
mian representatives of the true Carboniferous Megase- 
coptera (suborder Eumegasecoptera) . 
There are two modifications in the wings of some of the 
Protohymenoptera which were not considered above, be- 
cause they are obviously of no more than generic or specific 
importance. I refer to the broad wings of Permohymen, 
and the formation of a pterostigma in the Protohymenidse. 
Some students of insect phylogeny may object to the idea 
of deriving insects with broad wings like those of Permo- 
hymen from insects with narrow or subpetiolate wings 
like those of the Carboniferous Megasecoptera; for petio- 
lation is usually considered a modification of the normally 
