434 STUDIES IN AUSTRALIAN NEUROPTERA, viii., 



Ithone fusca, viewed from the side. Tt will be seen that the 

 structure of the coxse of the middle and hind legs is the same 

 as in the older Lepidoptera, a special piece of the epimeruin (epm) 

 being separated off from the principal part of the sclerite, and 

 attached posteriorly to the coxa in question. The position and 

 shape of the two large thoracic spiracles also resemble those of 

 the older Lepidoptera. The prothorax is more primitive than in 

 any known Lepidoptera, the pronotum being well developed, and 

 the pleurum definitely divided into two parts. 



Siiodgrass(8) and Crampton and Hasey(2) have shown that the 

 character of the specialised cox;e is common to the Mecoptera, 

 Trichoptera, Megaloptera, Planipennia, and Lepidoptera ; but 

 Ithone appears to show this more clearlv than other Lacewings, 

 possibly because of its greater robustness. 



The Ithonidce might also very appropriately be named the 

 "Cockroach-Lace wings," since they exhibit certain superficial 

 resemblances to Cockroaches. Their quick powers of running, 

 the peculiar texture and "feel" of their wings and bodies, their 

 fondness for running over one in the field, and their aptitude at 

 hiding away in dark places, are all characters that suggest a 

 resemblance to these insects. Moreover, as I hope to show 

 later, their internal morphology shows that they are more closely 

 related to the Cockroaches than these superficial resemblances 

 would suggest. 



In conclusion, I should like to remark that the very specialised 

 life-history of this family proves it to be a very early side-branch 

 of the Planipennia, lying well off the main line of descent of 

 present-day groups from the original Prohemerobiid types of the 

 Trias and Lias. As this life-history is by now almost com- 

 pletely worked out, I shall hope to give a full account of it in a 

 future paper. 



Note on the mouth-parts of the Ithonidce. (Text-fig. 6). 



Text fig. 6 shows the mouth-parts of the male of Ithone fusca 

 Newm., for comparison with those of other archaic Planipennia, 

 such as Psychopsis (10, p. 8 12, Text-fig. 12). 



