INTRODUCTION. XXI 



represent in their general characters, the NOCTU^E-NONFASCIAT^E of 

 Borkhausen and the NOCTU^E-FASCIAT^E of the same author. 



It has always been the aim of those who have attempted to 

 classify our species to form a linear arrangement of the lepidoptera, 

 in which each species should be closely allied to the one above and to 

 the one below it. Such a method must be of necessity impracticable. 

 As our knowledge of the development of species increases, so such an 

 idea as linear arrangement sinks into impossibility. Certain variations 

 leading to specific developments are thrown off from a parent stock ; 

 they reach a certain limit which may be extensive or otherwise ; and 

 as they are found, owing to altered conditions (geological, climatic, &c.) 

 to be suitable or unsuitable, naturally extend considerably or otherwise 

 die out. That is to say, suitable environment will carry on the 

 development once begun, and for a time, whilst such suitable conditions 

 exist, a linear arrangement may to a certain extent be followed, to be 

 again, however, broken up by outside circumstances, whenever they 

 become unsuitable. Besides, the very origin of specific forms, by 

 means of which branches from an original stock may develop into 

 distinct species in different directions, is against a linear arrangement 

 at the outset, and hence all attempts to form a linear arrangement 

 have proved futile. 



I do not propose to enter into the wide subject of classification 

 in detail, for which indeed I have no knowledge, but to consider a few 

 points in the classification of the NOCTILZE, especially with regard to 

 some aberrant species and genera. And here I may add that in my 

 work I have adopted the system of Guenee generally, not because I 

 believe in its infallibility, but because it was based on the study of 

 the early stages as well as the imago, which, indeed, seems to be the 

 only rational method of obtaining natural affinities, and it must be 

 confessed partly also, because of my ignorance and inability at the 

 time to suggest more natural lines and thus strike out a path for 

 myself. 



Guenee, as I have before remarked, divided the NOCTU^E into the 

 NocTTLE-TRiFimE and NOCTU^E-QUADRIFID^:, including in the former 

 term all the families represented in Britain and mentioned in ' The 

 British Noctuse and their Varieties,' down to vol iv., p. 14, whilst the 

 following portion of the work to vol. iv., p. 60 consists of the NOCTUJE- 

 QUADRIFID^E. The DELTOIDES, dealt with from p. 60 to the end of 

 this work, are treated by Guenee as a division equal in classificatory 

 value to the whole of the NOCTUJE. 



Guenee places under the sub-class Bombyciformes, Gn., the three 

 families Cymatophoridce^.-S., which he himself calls Noctuo-Bombycidai, 

 Bryophilidce, Gn. and Bombycoidce, Bdv. Staudinger, on the other 

 hand, places the first family in the BOMBYCES, retaining the two last in 

 the NOCTU^E. This would appear, in a measure, to be the better method, 

 as the species in Noctuo-Bombycidce have no very close affinities with 

 Bombycoidce. It must be borne in mind though, that Staudinger 

 classifies rather peculiarly, for whilst he sub-divides the BOMBYCES into 

 no less than fourteen families of equal value to wit 1. Nycteolidce, 

 H.-S. ; 2. Lithosidce, H.-S.; 3. Arctiidce, Stephs. ; 4. Hepialidce, H.S. ; 

 5. Cossidce, H.-S. ; 6. Cochliopodce, Bdv. ; 7. Psychidce, Bdv. ; 8. Liparidce, 

 Bdv. ; 9. Bombycidce, Bdv. ; 10. Endromidce, Bdv. ; 11. Saturnidce, 

 Bdv. ; 12. Drepamdidce, Bdv. ; 13. Notodontidce, Bdv. ; 14. Cyma- 



