274 MICHIGAN SURVEY, 1908. 



"V. kunteri also occuiTs right to the coast but is very much rarer 

 west of the Great Lakes than the other species mentioned. I have it 

 from Nova Scotia and also took it on Vancouver Island. 



"Basilarchia arthemis extends from the Atlantic coast to the Kootenai 

 Lakes, when its place is taken by B. lorquinii. Anosia plexippus a mi- 

 grant and may turn up at any place where Asclepias grows, but is 

 much rarer in British Columbia. 



"Epidemia epixanthe. — ^This is the only species I have some doubts 

 about. There is no doubt that some of the records of epixanthe should 

 be of the rare and little understood species dorcas which occurs in the 

 Lake Superior region and into Manitoba. It is easily distinguished 

 from epiwanthe by its slightly larger size and the brilliant orange wash 

 on the under surface. Epixanthe I have only actually taken myself in 

 Ontario. Dorcas I have from Nepigon on Lake Superior the Bruce 

 peninsula and from Manitoba. West of that the form, for it is hardly 

 a variety, florus which is really only a dimorphic form of helloides 

 occurs, and has I think, sometimes been recorded as epixanthe. The 

 reference of florus to dorcus instead of helloides as a variety, which 

 was done by Dr. Dyar, has in my opinion no reason in it at all. 



"Amblyscirtes vialis. — This is nowhere very common but extends from 

 Atlantic to the Pacific coast. I have specimens from Halifax, Nova 

 Scotia and have taken it in Vancouver Island. It is more abundant 

 perhaps in the Lake Superior region than any other where I have col- 

 lected." 



The butterfly fauna of Isle Eoyale may well be compared to that of 

 the White Mountains of New Hampshire on account of the large number 

 of species common to both localities (cf. Scudder, '1)7, pp. 71-87). Much 

 the same resemblance holds for northern New England in general. So 

 far as United States is concerned Isle Royale is the western outlier 

 of the distinctly northeastern or Canadian biotic type. Perhaps the 

 Black Hills will show similar aflSinities, but farther west a marked 

 Eocky Mountain influence becomes apparent. It is of interest to note 

 that six of the eighteen species hibernate as butterflies and another 

 spreads each season into the region. This number includes the species 

 which are of the most northern range and one (F. cardui) which is 

 cosmopolitan. Four of the species, E. j-album, P. cardui, B. arthemis 

 and A. plexippus are known to flock, or migrate. There can be but 

 little doubt but that these characteristics are important factors in an 

 understanding of their geographic range, and are probably adaptations 

 which permit these species to maintain themselves in the region. Such 

 adaptations may have originated in response to the environment or the 

 possession of them have allowed the species to enter the region already 

 adapted to it. 



When the above listed species are grouped geographically they fall 

 into the following classes : 



1. Of general geographic range from Labrador, Newfoundland, north- 

 ern New England, southward on the Adirondacks, Catskills and Ap- 

 palachians, westward through northern Ohio, Indiana, Wisconsin to 

 Alberta, and southward on the Rocky Mountains, British Columbia to 

 Alaska. 



