1922] Crampton — Relationship of Hemiptera-Homoptera 33 



shown in Fig. 32, there is a pronounced similarity between the 

 two types of wings, especially in the nature of the anal veins, and 

 the cubital and subcostal bars. The character of the median 

 vein is also quite similar in both, although the radial veins are 

 not quite so much alike in the two insects. While there is con- 

 siderable evidence pointing to the Protoblattids as the probable 

 precursors of certain primitive types of Neuropterous wings, 

 some of the Neuropterous types, on the other hand, have re- 

 tained certain Palseodictyopterous characters which suggest that 

 they hark back to Palseodictyoptera-like forebears. Handlirsch 

 suggests that the Megasecoptera represent the precursors of 

 the Neuroptera, and certain tendencies in the Megasecopterous 

 wing, such as the tendency toward the anastomosis of the 

 radial sector, media, and cubitus, are certainly very suggestive 

 of similar tendencies in the wings of certain Neuroptera, I 

 would not derive the Neuroptera directly from the Megasecop- 

 tera, however, as Handlirsch does, since the Neuropterous wings 

 evidently partake of certain characters in common with the 

 Protoblattids in addition to preserving certain features suggestive 

 of the Palseodictyoptera, so that all of these lines of descent 

 apparently either branched off near the base of the common 

 Protorthopteron-Protoblattid stem, or they parallel each other 

 remarkably closely as we trace them all back to their common 

 Palseodictyoptera-like ancestors. 



In the nature of the branching of its anal, cubital, and median 

 veins, Eugereon, the supposed ancestor of the Hemiptera and 

 Homoptera (Fig. 31) is apparently a Palseodictyopteroid insect 

 resembling, in some respects, the Palaeodictyopteron shown in 

 Fig. 33, while in many features the wing of Eugereon is very 

 suggestive of the Megasecopteron type. The primitive type of 

 Homopterous wing shown in Fig. 29 is not very similar to 

 Eugereon' s wing (Fig. 31), and it would be very difficult to derive 

 the primitive type of venation exhibited by the Homopteron 

 Hotinus (which is more like a Neuropterous or Protoblattid 

 type) mentioned above, from a wing such as that of Eugereon, 

 since the latter appears to be somewhat more specialized than 

 the venation of Hotinus. Taking all of the facts into con- 



