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Psyche 
[December 
(1893) and Lameere (1917), and we can now compare 
them with the corresponding features of the Protohymen- 
optera. All of the Megasecoptera possessed a pair of long 
multi-segmented cerci, identical with those which we have 
observed in the Protohymenoptera ; no other insects which 
have been found (except a few Paleodictyoptera) had 
cerci of such a nature. The segmentation of the thorax 
and abdomen, the structure of the antennse, and the con- 
tours of the head were also very similar to those of the 
Protohymenoptera. The fore legs of some of the Megase- 
coptera were undoubtedly raptorial (Lameere, 1917), while 
others were of the simple walking type, resembling those 
of the Doteridse. The exact number of tarsal segments in 
the Megasecoptera is not known, but Lameere believed 
that he could distinguish five segments in one of the Com- 
mentry fossils. In Doter, as we have seen above, there 
were only three tarsal segments, but this difference is 
really of no significance, for in some of the recent orders 
the number of tarsal segments is equally variable. 3 
The body structure of the Protohymenoptera, therefore, 
not only agrees with Martynov's conclusions, but adds 
strong evidence in support of the view that the Proto- 
hymenoptera were very closely related to the Carbonifer- 
ous Megasecoptera. 
Let us now compare the wing venation of the two 
groups ; can we derive that of the Protohymenoptera from 
the one found in the Megasecoptera? The most complete 
and detailed figures of the megasecopterous wings are 
those contained in Brongniart’s classic account of the 
Commentry fossils, and I base my discussion of these 
wings chiefly on his work, for there are no unquestionable 
Megasecoptera known from the American Carboniferous. 
In particular, Brongniart’s enlarged diagram of the wing 
of Aspidothorax is very useful and is reproduced here 
(text fig. 3). When we compare the wing of Protohymen 
with this figure, we at once note that there are two longi- 
tudinal veins less in the Protohymenopteron than in the 
Megasecopteron. In Aspidothorax the radial sector origi- 
nates before the middle of the wing and gives rise to three 
As in the Plectoptera, where the number is from five to one. 
