VI INTRODUCTION 



respond as far as possible with that advocated by Dr. Seitz 

 in his Macrolepidoptera of the World ; we have revised the 

 Lycsenid and Hesperid genera to make them conform with 

 the rules of nomenclature as adopted by the International 

 Congress, and in this connection would express our appre- 

 ciation of the kind assistance rendered us by Mr. Bethune 

 Baker of Edgbaston, England, in determining the Lycaenid 

 genera which it is advisable to employ. 



In the SPHINGID^E we have followed Rothschild and 

 Jordan's masterly revision, making only a few generic 

 changes which we considered advisable. 



The general scheme of the ARCTIID^: and NOCTUID./E 

 has been that of Sir George Hampson's Catalogue of the 

 Lepidoptera Phalna3 of the British Museum, but in the 

 latter family we have been obliged to change the generic 

 conceptions considerably as the method employed by Hamp- 

 son in determining generic types is not permissable accord- 

 ing to the International Rules; these changes have been 

 made the subject of a special paper published recently. 



In the GEOMETRID^E we have followed Mr. L. B. Prout's 

 careful revisions in the Genera Insectorum and in Seitz's 

 Macrolepidoptera as far as published, making only such 

 changes as our more extended acquaintance with the North 

 American species and their types has rendered necessary; 

 our most hearty thanks are due Mr. Prout for the invaluable 

 aid he has so cheerfully given us in connection with the 

 difficult genera of this group. 



The PYRALHXE remain more or less as listed by Dr. 

 Smith in so far as the genera are concerned, but numerous 

 shifting of species has been necessitated, especially in the 

 Phycitinae, as our knowledge of the same has been in- 

 creased by long series of both sexes. 



