INTRO D UCTION. 1 9 



of violticea, become diiiiorphicj one form resembling the 

 males of the same found farther north, the other being 

 uniformly dark above (violacea-nigra). In the southern 

 part of its range, the latest individuals (neglecta) of the 

 first brood are usually much larger than the members of 

 the second brood, all of which are otherwise of the same 

 type. This butterfly flies not only from Hudson Bay to 

 Georgia, but also from the Atlantic to the Pacific, and in 

 California we have a new form (piasus), hardly distinguish- 

 able from neglecta, which appears to be double-brooded in 

 the south but to show no difference between the broods. 

 Farther north, however, near tlie British boundary, the 

 conditions of New England are at least in part repeated, 

 wliile in Arizona an ashen variety (cinerea) occurs. 



The different forms assumed by Eurymus eurytlteme 

 have caused their description as distinct species on four or 

 five occasions. It, too, has an immense range. In Texas 

 the cycle begins in November (the summer and not the 

 winter interfering with its activities) with a yellow type 

 (ariadne) succeeded by a yellow-orange tyi:>e (keewaydin) 

 and finally by an orange type (amphidusa), each a distinct 

 brood, the last-named indeed double-brooded; with the in- 

 crease of temperature, the size and the dej^th and brilliancy 

 of color increase; the form keewaydin has a sexually di- 

 morphic female, one resembling the male in ground color, 

 the other pallid (keewaydin-pallida), and the form amphi- 

 dusa is similarly favored (amj^hidusa-alba). In the north- 

 ern part of the range of the species, the earliest (May) form, 

 a yellow one, differs so much from the earliest (November) 

 type of the south as to be given a distinct name (eriphyle), 

 and when keewaydin and amphidusa have had their turn, 

 it again appears in the latter part of the season, and 

 though the autumn form has not received a distinct name, 

 it can be distinguished from the spring form, at least in 



