revision of the genus Argynnis. 553 



whether this difiference is constant. I agree with Graeser 

 in thinking that it is better placed near chariclea and 

 freija than before selene, where Staudinger arranges it. 



A. angarensis is very close to selenis var. sibirica, and 

 perhaps can only certainly be distinguished in the male 

 sex by the row of silvery white marks on the border of 

 the hind wing below. The female, however, of which 

 sex I have four perfect specimens, seems paler in colour 

 and rather larger than the corresponding sex of selenis. 

 Graeser, who has taken both in abundance, does not 

 question their distinctness. 



A. freija is a species of immensely wide range, but 

 which does not seem to vary in the least, six pairs 

 taken by me in the Yellowstone Park being indis- 

 tinguishable from average Lapland and Swedish speci- 

 mens. Its range, however, differs much in the Old and 

 New Worlds, for whereas in Europe it is not found south 

 of 58° or 59° N. in Estland, and 60° in Sweden, and extends 

 to about 70° N. in Lai^land and Siberia ; in the Eocky 

 Mountains it extends south to at least 40° in Colorado, 

 and is not known to occur farther north than Fort Simpson, 

 about 62° N. The difference in climate and vegetation of 

 the two continents at similar latitudes must explaui 

 this, and only the presence of the continuous high range 

 of the Eocky Mountains can account for its extending 

 so far to the south in Colorado. The form described as 

 tarquinius is, I think, only a smaller darker arctic var., 

 which occurs also in British Columbia. 



A. amathusia. — A well-known and little-varying species, 

 as far as my experience goes ; but I possess no eastern 

 or Asiatic specimens. Eussian specimens, however, are 

 paler and somewhat smaller than Swiss ones, as are 

 some from the Italian valleys of the Western Alps. 

 Schilde, in his paper on Finland butterflies, Stett. Ent. 

 Zeit., 1873, p. 176, says that freija, chariclea, and 

 amathusia hold as near a relationship to each other as 

 aphirape, ossianns, and triclaris, and that he finds only 

 trifling differences between the two latter ; but I cannot 

 at all agree with this, as amathusia is fully as distinct 

 and more easy to separate, than many species in this 

 group ; and if it was, as he seems to suggest, the alpine 

 representative of either chariclea ov freija, would probably 

 have retained its place only in the highest and coldest 

 part of the Alps, whereas it flies in grassy glades among 



2q2 



