BY R. J. TILL YARD. 735 



Petersen's two papers form a basis, without which it would have 

 been inadvisable for any Australian entomologist to undertake 

 the study of this Order; and that Australian scientists, as a 

 whole, must be deeply indebted to him for his excellent and 

 painstaking work. 



Before Mr. Petersen's papers were published, I had already 

 studied a considerable number of rare Xeuropterous insects in 

 my own Collection. Many of these were sent to him for his 

 opinion, and I now desire to thank him for his valuable advice 

 and help in this direction. In many cases, it was quite impos- 

 sible to determine a species as definitely new, until it had been 

 compared with some old type, owing to the often glaring inade- 

 quacy of some of the older published descriptions. In order to do 

 justice to the excellent work of McLachlan and others, it is only 

 fair to state that the jjrincipal obstacle in this respect has always 

 been Walker,* whose work is here strongly recommended to any 

 Australian entomologist as a model of how descriptions of insects 

 should not be written. Fortunately, Mr. Petersen has seen 

 Walker's types, and we may now hope that the fog caused by that 

 painstaking "manufacturer" of new species has been permanently 

 lifted. 



The species described as new from my own Collection, together 

 with a number sent to me for study from other parts of Aus- 

 tralia, will be published in No. 2 of this series of papers. Mean- 

 while, as the whole scheme of classification hinges chiefly on the 

 wing-venation, it was found necessary to deal with this matter 

 first of all. In No.l of this series, therefore, I offer the results 

 of my study of the pupal wing-tracheation of the Myrmeleonidft', 

 together with some remarks on certain special structures in the 

 imaginal venation which are of value to the systematist. 



The species selected for study was Myrmfieleon uniseriatus 

 Gerst. Its larva is perhaps the commonest and most easily 

 noticed of the Ant-lions of the Sydney district. This species 



* Catalogue of Keuropterous Insects in the Collections of the British 

 Museum, 1853. 



