INTRODUCTION. 



the habitat, and in general, the collection from whence the 

 specimen has heen purchased, or procured in exchange, is 

 also marked ; as it often gives some authenticity to its 

 history. 



In the adoption of generic and specific names, it has been 

 thought right to use, wherever it was possible, that which was 

 first applied to the species. As far as regards the specific 

 names, there is comparatively little difficulty in the applica- 

 tion of this simple rule ; but generic names have been used 

 by different authors in senses so widely different, and the 

 groups which they were meant to designate have been so va- 

 riously extended or restricted, that it is no easy matter to 

 determine, where several names have been used, which of them 

 ought to be preferred. 



If the generic name adopted be different from that first 

 employed for the species after the establishment of the Lin- 

 nean system of nomenclature, the name under which it was 

 first described follows as a synonyme, and where the Insect 

 has received more than one specific name, those names are 

 also given, as being sufficient for all purposes of identification. 



These are followed by a reference to a few of the best ori- 

 ginal figures of the species. 



In those cases where the two sexes of the same species, or 

 any particular individual state or variety belonging to it, have 

 been differently named, the name or figure exclusively apper- 

 taining to the state or individual is placed after the indication 

 of the specimen to which it applies. 



