AMERICAN LKPIDOPTERA. 245 



A < I.4f«KIFI<\4TIO\ OF TIIF <;KOnFTiei\A OF 



NORTH AHFKICA. WITH DFKC'KIPTIOIVS 



OF NK\¥ GE\ERA A:V» $>il>£<'IKS. 



HY KEV. GEO. D. HUL8T. 



As tlie result of" the work of systematlsts, two methods of ckissifi- 

 cation are found in our lists and text books. The first is in eonnnon 

 use in iMirope, and is the system of Lederer. The second is in use 

 in America, and is the system of Guenee. Lederer's system, pub- 

 lished in 1853, was far in advance of anything published before him, 

 and, as based in large part upon structure, has deserved the respect 

 it has always received. Guenee's system was given a life on this 

 side of the ocean by the fact that Dr. Packard, in his Monograph, 

 closely followed it, and that Monograph has made our lists and given 

 us our names. This system, professedly attempting to cover every- 

 thing, is exact in nothing, and as a system is absolutely without 

 worth, and, apart from Dr. Packard's following, has never had any 

 recognition. 



In 1892, Mr. Meyrick pul)lished a "Classification of the Geome- 

 trina of the European Fauna" (Trans. Ento. Soc. London, 1892, 

 part 1, pp. 53-140), in which he endeavored to arrange the family 

 on the basis of invarial)le structure. This classification does not as 

 yet seem to be adopted, but is, in many respects by far the best yet 

 proposed, and is the result of wide comparative study and consistent 

 generalization. It is this system which, in the greater part, I have 

 followed. And yet I have made in one respect at least a radical 

 departure from it. Mr. Meyrick lays down as one of the funda- 

 mentals of his classification the following rule : " No genus, family 

 or higher group, is tenal)le unless distinctly separable from all others 

 by points of structure, which, whether singly or in conjunction, are 

 capable of accurate definition. If a systematist is not able to define 

 by a clear and not simply comparative character, the distinction 

 between two genera, he is bound to merge them together." This 

 rule is a most excellent one, but Mr. Meyrick, in his rigid and con- 

 sistent application of it, gives it an interpretation not warranted in 

 [)ractiee, for he makes not difference in structure, but difference in 



TRANS. AM. ENT. SOC. XXIII. JULY, 1896. 



