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Mr. S didder presented the following paper : — 

 On the genus Colias in North America. By Samuel H. 



SCUDDER. 



The determination of the different species of the genus Colias, 

 their limits and relations to one another, is one of the most difficult 

 undertakings in the study of the diurnal Lepidoptera, and is ren- 

 dered by no means less so by the confusion into which they have 

 been thrown by those who have written upon them. Menetries, it 

 seems to me, is almost the only one v/ho has brought to their inves- 

 tigation any considerable degree of acumen or of perseverance. 

 Among the North American species there is as great a degree of 

 confusion as there is anywhere ; so that it is necessary for one 

 attempting a fair and impartial investigation into the species on 

 this continent, to entirely separate himself, at the start, from a 

 knowledge of opinions previously expressed in regard to them, if 

 he would not become hopelessly entangled in an intricate web of 

 misconceptions and disagreements. I have had the opportunity 

 of examining a very large number of specimens from the Eastern 

 States and from the Pacific Coast, a considerable number from 

 Labrador and from the central boreal regions, and a few from the 

 States bordering the Mississippi River. The collections which I 

 have used have been those of the Museum of Comparative Zoology, 

 Cambridge ; the very beautiful series of Mr. W. H. Edwards, at 

 Newburgh, N. Y. ; the collection of butterflies of the Lyceum of 

 Natural History, Williams College, Mass., and my own specimens, 

 which are mainly from New England. 



In treating of the genus Colias in North America, we should 

 first of all separate from them C. Coesonia StoU and C. Wosnesenski 

 Men. ; of which latter, according to Edwards, in Morris's Synopsis, 

 C. Eurydice Boisd. is a synonyme, — these must be placed in the 

 genus Zerene Hiibner. 



Of the number of species found south of the northern boundary 

 of the United States, I cannot form any settled opinion, nor can I 

 of their range; for, though I have seen a very large number of 

 specimens, these have been limited mostly to the extreme eastern 

 and western borders of our country ; yet I have very strong doubts 

 whether there are anywhere more than two species, C. Philodice 

 Godt. and C. Eurytheme Boisd., — the former an Eastern species, 

 but found so far west as Missouri ; the latter a Western, but found 

 so far east as the Mississippi, and perhaps even to the Atlantic border, 

 south of New York. The former is the only sulphur-yellow Colias 

 I am acquainted with in the United States, the latter the only 

 oranwe-tinted species I know of within its borders. To C. Philodice 



