1922] Cramyton — Relationship of Hemiptem-Homoptera 25 



representatives of the Protorthoptera are compared with certain 

 Protoblatticls, it may readily be seen that the branches of the 

 median and radial veins are also much the same in both groups 

 of 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 Palseo- 

 dictyoptera. I do not beHeve 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 Synarmogoids ; 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 Hadentomoid 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 Hadentomoid 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 



