1922 ] Crampton — Relationship of Ii emiptera-H omoptera 
25 
representatives of the Protorthoptera are compared with certain 
Protoblattids, it may readily be seen that the branches of the 
median and radial veins are also much the same in both groups 
ol insects, so that the Protoblattid types of wings may be re- 
garded as representing as nearly as any known forms, the pre- 
cursors of the Protorthopterous types of wings; and the Proto- 
blattids serve to connect the Protorthoptera with the Palaeo- 
dictyoptera. I do not believe that the Protoblattids themselves 
are to be derived directly from the Palseodictyoptera, however, 
but their ancestors were possibly intermediate between the 
Palseodictyoptera and the ancestors of the Synarnrogoids; and 
the Protorthoptera possibly sprang separately from the same 
stock, although the Protorthopterous and Protoblattid lines 
of descent apparently merge as we trace them back to their 
common stem, so far as the evidence of the wing veins would 
indicate. 
In the reduction of the anals, the shortening of the cubital 
bars, and the reduction of media to two branches, the fore wing 
of the Haclentomoid shown in Fig. 10 presents many features 
suggestive of a rather close relationship with the Protorthoptera, 
such as the ones shown in Figs. 28 or 26, and the nature of the 
radius and subcosta is quite similar to that of certain other 
Protorthoptera. On the whole, however, the type of Hadento- 
moid wing shown in Fig. 10 might more readily be derived 
from the type of Protoblattid wing shown in Fig. 12, and it is 
quite possible that the line of development of the Hadentomoids 
arose from ancestors anatomically intermediate between the 
Protoblattids and the Protorthoptera very near the point where 
these two lines of descent began to diverge from their common 
Protoblattid-like forebears. The Hadentomoicl type of venation 
is a very important one in suggesting a possible starting point 
in the the development of the types of venation occuring in the 
Embiids and their allies, as will be shown later. 
The character of the anal, subcostal and cubital veins of the 
Mixotermitoid fore wing shown in Fig. 25, is very suggestive of 
both Hadentomoids (Fig. 10) and Protorthoptera (Fig. 28), 
.and the character of the median vein is somewhat suggestive of 
