AUTHOR S PREFACE. Vll 



two of which are of peculiar interest on account of their 

 habits and structures — viz., the Zetizeridce and Ilepialidce, the 

 latter being considered by many Entomologists to be the 

 most archaic group of all existing Lepidoptera^ except the 

 MicropierygidcB and Eriocephalidce. 



As vol. V. is intended to include the whole of the remaining 

 families of Lepidoptera, no space would have been available 

 for other matter than the descriptive part of the work, unless 

 room had been found for it by transferring a considerable 

 portion of our account of the Noctucz to the present volume. 

 It was, however, considered undesirable by the Editor to 

 divide the NoctitcE in this manner, and therefore, instead 

 of publishing part of the Noduce in vol. iv. and the re- 

 mainder in vol. v., in addition to the remaining families, 

 it was decided to adhere to the scheme set forth in the 

 Preface to vol. iii., and to issue with the present volume 

 the whole, or nearly the whole, of the supplementary matter, 

 part of which was originally intended to appear in vol. v. 



Vol. iv., therefore, includes three sections besides the 

 descriptive portion. The first is Professor Westwood's letter, 

 referred to in the " Preface " to our vol. i., giving full 

 particulars of his work for Jardine's " Naturalist's Library." 

 It was important to place this letter on permanent record in 

 the present work, and the Editors of the " Entomologist's 

 Monthly Magazine " have kindly permitted me to reprint it. 



The second section contains a sketch of the various systems 

 of classification oiihQLepidoptcra,:^?, advertised in the "Preface" 

 to our last volume ; and the third section, which was originally 



