220 



-we cannot regard a certain amount of variation in the form of the 

 wing, of generic value. I believe then that we are justified in re- 

 garding Clemens' genus Exartenia equivalent to Eccopsisoi Zeller, 

 and our species should be referred to the latter genus. 



NOTES ON SOME NORTH AMERICAN LEPIDOPTERA. 



By Arthur G. Butler, British Museum. 



GEOMETRITES. 



It appears to me that no group of moths has got into greater 

 confusion than the Geoinctritcs, and I strongly suspect that the 

 principal cause must be sought for in in the want of definition in 

 this part of the work undertaken by M. Guenee ; whether that 

 eminent Lepidopterist was in a hurry to get through his work, or 

 "whether the publisher worried him, I do not care to inquire, but 

 he certainly failed to distinguish between reliable and variable 

 characters ; and, worse than that, he failed to separate the species 

 before him into natural groups; by this I mean to say that hav- 

 ing characterized a genus as possessing primaries with the outer, 

 margin angulated, M. Guenee was as likely as not to place in it 

 half a dozen species not possessing that character ; whereas, ac- 

 cording to description, he ought to have placed them in a suc- 

 ceeding genus. 



As this uncertainty in the outline of species primarily referred 

 to a genus has led to different authors forming entirely dissimilar 

 views in accordance with the named types in their collections, the 

 •evil has naturally increased tenfold since the publication of M. 

 Guenee's work, and the consequence has been a great multiplica- 

 tion of synonyms. 



The following Geometrites have been sent to us by Mr. H. 

 Edwards : 



ENNOMID^. 



EUTRAPELA FALCATA. Packard. 



Two examples exhibiting different color variation from the 

 Sierra Nevada. The genus is confounded with Choerodcs, C. trans- 

 ferens of Walker being the same as E. clemataria, a blunder due 

 to the vague description, — " les premieres a apex aigti et a bord 

 terminal droit ou coude en angle sur la 2 ," a door being thus 

 opened for the introduction by M. Guenee and all subsequent 

 authors, of species utterly unlike in outline of wing. 



OPISTHOGRAPTIS SULPHURARIA. Packard. 



Two examples from California: it comes near to nothing in 

 the museum series. 



" Endropia MADUSARIA. Walker.'' 



The species sent under this name seems to me to be the E. 

 effectaria of Packard's Monograph ; it certainly is not Walker's 

 species (which seems to me to be the same as that figured by 

 Packard), but comes nearer to E. pectinaria, tigrinaria, astyliisaria 

 •and propriaria of Walker's list. 



