PREFACE. 



Since the issue of the List of the Lepidoptera of boreal 

 America, in 1891, much has been done to increase our knowl- 

 edge of the order. Our conceptions of families and of their 

 relation to each other have changed, and our system has be- 

 come more scientific. No universal agreement has been 

 reached ; but such differences as exist will result in more care- 

 ful studies until substantial uniformity has been attained. 

 There have been monographic revisions of families and genera ; 

 some confined to our own species and published in America, 

 some of wider scope, published abroad. The critical studies 

 of American types in European Museums has been continued, 

 and very few species need now be marked as ' ' unknown ' ' in 

 any family. The changes made in these studies and the num- 

 ber of new species and genera described, demand a revised 

 edition of the earlier list, which is herewith presented. 



The old list enumerated 6020 species : the present list is 

 numbered to 7169, an apparent increase of 1149 species; but 

 this does not fairly represent the state of affairs, for in becom- 

 ing acquainted with the older, heretofore unknown species, 

 almost as many more recent names have dropped into the syn- 

 onymy : and on the other hand, I have arbitrarily dropped 

 some numbers at the end of the larger series to allow for addi- 

 tions, and in part that the numbers might in a way indicate at 

 least the superfamilies. About 290 numbers should be allowed 

 for this, and 75 may be added for synonyms and duplicated 

 species in the old list. This makes a net increase of about 

 930 species, and indicates a creditable activity among the 

 American students of the Lepidoptera. 



In the present list, the same principles that guided the prepa- 

 ration of the previous one were kept in view. It is intended 

 to be conservative, yet fairly representative of actual advances 

 in classification. It is not for the catalogue-maker to decide 

 upon the validity of species and genera except where he has 

 special knowledge, and I have, in general, accepted the un- 



