156 



IX. On the North American Geometridae in the 

 Collection of the British IVluseum 



BY AUG. E. GROTE. 



An interval of five years has elapsed since the publication of an 

 article by the late Coleman T. Robinson and myself/ upon the North 

 American Moths contained in the British Museum Collection 

 described by Mr. Francis "Walker. And now concurrent testimony 

 to the worthlessness of Mr. Walker's determinations is borne by Pro- 

 fessor Packard.* In comparing the results, reached independently 

 by Professor Packard and ourselves, their similarity must be consid- 

 ered as evidence of their accuracy. There are at the outset the fol- 

 lowing differences of treatment of the material discussed in our 

 respective articles to be borne in mind. We reviewed the entire col- 

 lection of North American Moths contained in the British Museum, 

 while Dr. Packard's jjublished Notes relate only to the Geometridae 

 and Pyralidae. Again, we merely corrected certain of Mr. Walker's 

 generic references and indicated the principal synonyms, whereas 

 Professor Packard refers to all of the species of the two families 

 above alluded to, contained in the collection under Mr. Walker's 

 determinations. 



In the present Paper I tabulate the results of these independent 

 observations on the Geometridae, where the same species has been 

 considered, so that an agreement or disagreement in these determi- 

 nations becomes more clearly exposed. And as to the fewer instances 

 where Professor Packard's determinations have not accorded with our 

 own, I would partly account for them by the more critical study which 

 Professor Packard has bestowed upon our Geometridae for several 

 years past, and have thus no doubt that the later determinations are 



1 Notes on the N. Am. Lepidoptera contained in the British Museum Collection and described 

 by Francis Walker ; Trans. Am. Ent. Society, July, 1868. 



2Notes on North American ]\Ioths of the Families Phalnenidae and Pyralidae in the British 

 Museum; 5th Ann. Rep. Peabody Academy of Science, July, 1873. 



