486 NEUROPTERA 



CHAP. XXI 



conditions of the Lepidoptera. It should be noted that the 

 head in Phryganeidae is the most important part from a 

 systematic point of view, and that fossils have been chiefly 

 identified from the wings ; this is a much more doubtful 

 character, as the wings of the Phryganeidae have a simple 

 system of neuration, and in shape have nothing very charac- 

 teristic. 



Extinct Order Palaeodictyoptera. 



This seems to be the fittest place to notice the existence of 

 some fossil remains from the Palaeozoic rocks that cannot be 

 fitly, or certainly, assigned to any of our existing Orders, and to 

 which the above name has consequently been given. These 

 remains consist chiefly of wings in a more or less imperfect state 

 of preservation, and it is therefore quite doubtful whether the 

 course of assigning them to a separate Order supposed to be ex- 

 tinct be correct. This is all the more doubtful when we recollect 

 that an Insect fossil, Eugereon bockingi, having the head with 

 mouth-parts of a Hemipterous or Dipterous nature, has been found, 

 the wings attached to it being such as, had they been found 

 separate, would have been considered to be Neuropterous, or at 

 any rate allied thereto. About forty-two forms of Palaeodicty- 

 optera are assigned by Scudder to a section called Neuropteroidea, 

 and may therefore be considered to have a special resemblance 

 to our Neuroptera. These Neuropteroidea comprise numerous 

 genera and no less than six families. Scudder's view is at 

 the best tentative, and is not very favourably received by some 

 entomologists. Brauer has, indeed, objected altogether to the 

 formation of this Order Palaeodictyoptera, and Brongniart has 

 published a list of the Palaeozoic Insects in wilich a system 

 of arrangement different to that of Scudder is adopted. In his 

 most recent work l Brongniart assigns some of these Neur- 

 opteroidea to the families Platypterides and Protodonates, which 

 we have previously discussed. The whole subject of these 

 Palaeozoic Insect remains is still in its infancy, and it would 

 not be proper to accept any view as final that has yet been 

 stated, nor would it be fair to dismiss the subject as unimportant 

 because of the great divergence of opinion amongst the authorities 

 who have investigated it. 



1 Insectes fossiles des temps primaires, 1893, p. 38. 



