-viii INTRODUCTION. 



These families embrace insects of such diverse structure 

 and habits, that they have been variously grouped by 

 different entomologists, and several of the groups have been 

 constituted distinct orders. The Bird-lice, for instance, are 

 •often spoken of as forming the small order Mallophaga, 

 and the Caddis-flies as constituting the order Trichoptera. 



The affinities between many of these families and certain 

 groups of insects, belonging to other orders, are very 

 remarkable, and appear to indicate that the Neuroptera are 

 essentially of an archaic and ancestral type ; and this idea 

 is borne out by the numerous species of gigantic fossil 

 neuropterous insects which have been recently discovered 

 .and described. 



As illustrating the actual affinities of certain families 

 of the Neuroptera, to families belonging to other orders 

 of insects, the following examples may be cited : The 

 Termitidae, or White Ants, are somewhat allied to the 

 Hlattidgp, or Cockroaches ; the Perlidse, or Stone-flies, to the 

 Phasmidae, or Walking-stick Insects ; whilst the Trichoptera, 

 or Caddis-flies, are unquestionably very closely allied to the 

 Lepidoptera, being in fact now generally regarded as 

 the nearest living representatives of the ancestors of that 

 extensive and important order of insects. 



In the present work only the larger and more generally 

 interesting families of the Neuroptera are dealt with, and 

 even in the families which are described, very much more 

 work remains to be done by future naturalists. 



The geographical distribution of the various species in 

 New Zealand is most imperfectly known at present, being 

 based on the somewhat disconnected observations of a few 

 isolated naturalists. The conclusions arrived at under this 

 heading must therefore be regarded as provisional, and, as 

 knowledge increases, subject to revision. 



