1922] Crampton — Relationship of H emiptera-H omoptera 
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 Protoblatt.ids 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 Pal£eodictyoptera-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 
Protoblatticls 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 
Palceodictyoptera-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 Palaeodictyopteroid insect 
resembling, in some respects, the Pal£eodictyopteron 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- 
