412 ON THE GENUS CORDULEPHYA, 



found in the Aeschnidce and Libellulidce took their rise. As 

 it is not the purpose of this paper to deal fully with this 

 question, I will now proceed to consider the development of 

 Cordidephi/a from this new standpoint. 



The Eucorduliaa relationship of Cordnlephya being so 

 clearly indicated in its early stages, as well as by some of the 

 imaginal characters, we have to seek an explanation of the 

 remarkable character of the wing- venation, and its appar- 

 ently Idocordidutn connection, from the premises above 

 stated. It is, I think, evident that Cordulephya, instead of 

 being, as Needham supposed, an archaic and generalised 

 form, is (t highly specialised and reduced form, descended 

 from the same ancestors as the rest of the Eucordulina, after 

 that group had become differentiated from the Idocordulina. 

 In that case, the resemblance in wing-venation to the Idocor- 

 dulina is purely a resemblance of converyence, brought about 

 by extreme reduction. I give the following reasons in sup- 

 port of this statement : — 



A. The absence of generally recognised archaic characters 

 in the venation. — Notice particularly the freedom from 

 supernumerary cross-veins, the strong formation of the bridge 

 with no supplementary bridge-crossveins, and the conver- 

 gence of M4 and Cuj in the f orewing ; also the arculus-sectors, 

 which shew some tendency towards fusion. 



B. The rcniarhable flight and habits of the imago. — These 

 seem to me to point to a high degree of specialisation, brought 

 about by a strenuous light against adverse conditions. 



C. A comparison of the wing-venation of the two species 

 C. pygmcta and C. ntontana. — This is most important. First 

 of all, throughout Australia, wherever mountain-forms are 

 found, they are almost certainly more archaic than the 

 allied coastal forms. The admittedly archaic types, such as 

 Telephlc})ia, I'etalura, Austroaeschna, Synthemis, and Syn- 

 lestes are either entirely confined to the mountains, or shew 

 greater specialisation in their coastal representatives. The 



