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THE PANORPOID COMPLEX. 

 A Study of the Phylogeny of the Holometabolous Insects, 

 WITH Special Reference to the Subclasses Panorpoidea 



AND NeUROPTEROIDEA. [INTRODUCTION]. 



By R. J. TiLLYARD, M.A., D.Sc, F.L.S.. F.E.S., Linnean 

 Macleay Fellow of the Society in Zoology. 



Introduction. 

 Section i. — Definition of the Complex. 

 In his great work upon the Phylogeny of the Orders of Insects. 

 Handlirsch (2) divides the whole of the Holometabola into four 

 Sub-classes, as follows — 



In making this division, Handlirsch widely separates the first 

 two of these Sub-classes from the last two, placing between them 

 not only what we may, for convenience, term the three Amplii- 

 biotic Orders (Odonata, Plectoptera, and Perlaria), each of 

 which he elevates to the rank of a Sub-class, but also the Embi- 

 daria, which he also considers to be a Sub-class. For the 

 Hymenopteroidea and Coleopteroidea, Handlirsch indicates a 

 descent from a JJlattoid type of ancestor. For the JMeuropter- 

 oidea and Panorpoidea, he is more inclined to a Palseodictyopt- 

 erous type of ancestor; indeed, he definitely states his belief that 

 the Neuropteroidea are descended directly from the Palaiodicty- 

 optera, while he considers the Panorpatre, and hence the Panor- 



