PREFACE. IX. 



ignorance is rarely, if ever, convinced with anything that attempts to 

 lead it by easy stages to a higher level, and we have little hope that 

 the entomological collector will be raised to a more exact method 

 of description by calling a " variety " a " subspecies," an " aberra- 

 tion " an " individual variation," a " superfamily " a " family," and 

 a "family" "Section A or B" as the case may be. Nor do we 

 see the reason for the alteration of the generally accepted tribal 

 termination " idi " for " icae," a change that makes neither for greater 

 uniformity nor simplicity. With their sinking of the "subgenus" we 

 quite agree ; if it is to be held, as they (and we) hold, that " the genus 

 is the classificatory unit one category higher than the species and com- 

 prising one definable group of species," then a subgenus has no 

 place ; in its present use by authors the subgenus replaces the genus, 

 the genus the tribe, and so on, the result simply being an application 

 of terms to groups differently called by almost all other biologists, 

 and hence making for confusion. 



These are the main points which a careful study of Rothschild 

 and Jordan's magnificent work suggests to us are in need of 

 explanation, showing how the differences between their work and 

 ours have arisen. The wisdom of sinking a large number of well- 

 differentiated, and what have hitherto been held as clearly distinct, 

 species as varieties, is not for us to judge; we have insufficient 

 knowledge to deal with the matter. 



It will be seen that the arrangement of our " Catalogue," at the 

 end of this volume, differs considerably from the order adopted in our 

 work. During the progress of a work of this magnitude the author is 

 always having, as it were, to consider fresh facts that modify his 

 earlier judgments, formed on less material, and to make this change 

 clear to his readers. In fact, he educates himself by his work 

 and is really only fitted to commence the writing of his book 

 when he concludes it. If one carried out this mental 

 attitude to its logical conclusion one suspects that no book would 

 ever be written, for, as it is a plea for perfection, and nothing perfect 

 from this standpoint can exist, it follows that each successive stage 

 of work would only lead to the desire for a better. This is only 

 put forward as a plea for lenient consideration of the many imperfections 

 and illogicalities that will be self-evident to every serious student as he 

 follows our work, and as a means of adding that the order of the 

 Catalogue, so far as a linear order means anything, represents a some- 

 what maturer view than the order of the book itself. 



To my collaborators, I desire to express my unqualified thanks 

 — to Dr. T. A. Chapman, Messrs. A. W. Bacot, W. J. Kaye and 

 L. B. Prout my very best thanks are due. The references to their 

 work will show how greatly I am indebted to them, whilst the kind 

 help of Messrs. G. C. Bignell, C. R. N. Burrows, J. C. Dollman, 

 W. F. Kirby, A. Sich, and others, must not pass unacknowledged. 

 I had hoped that the book would have been published some months 

 since, but various contingencies, mainly relating to printing, have 

 delayed the work till almost the end of the year before completion. 

 Still, I trust now that it is completed, it will meet with the approval 

 of all those serious students of lepidopterology who are generous 

 enough to support my work. 



It has been continually urged, by Mr. Bateson and others, since 



