PEEFACE. 



At the commencement of this Essay I must draw 

 attention to the fact that, as yet, no serious biolo- 

 gical work has been attempted with the North- 

 American Noctuidse. The internal structure is yet 

 a mystery to us, or at best we can judge it from 

 Mr. Burgess's admirable work on Dcmaus, or get 

 some notion of it from the observations brought 

 together in Dr. Packard's ' Guide to the Study of 

 Insects.' Some work, not perhaps so extended, but 

 in the line of Professor Huxley's exhaustive volume 

 on the Crawfish, is needed on any of our common 

 species of Noctuidee. This Essay deals with the 

 external structure, as to which I do not find much 

 notice taken by the older English lepidopterists, 

 except by Stephens, whose discriminations of genera 

 I find very good and anti cipatory of the characters 

 afterwards used by Lederer. I find, also, in Hiibner's 

 ' Verzeichniss' (and here, I fear, I shall hardly con- 

 vince Mr. W. H. Edwards) evidence that the aiithor 

 had made some examinations of characters, or else 

 som e very extraordinary guesses, as, for instance, in 

 the association of the genera under the BomhijcidxB, 

 where he was clearly ahead of his time. The genera, 

 as established, are dependent on comparative cha- 

 racters or on details of absolute structure, these 



