l.'»l Till-: ( WAMIAN I'VTuMtlUXilbT. 



were in fine condition. No pairs in copulation were seen, and no eggs 

 were found upon examination of a large bunch of the cuiquefoil. The 

 bright condition of the butterflies, absence of eggs, etc , indicated one of 

 two things — either dorcai appears much later in the northern part of the 

 State than in the southern, or the season of 1909 was unusually lite. The 

 latter was undoubtedly the case, for the species was taken in good con- 

 dition in both sexes in (-)akland County the same summer on July 25th, a 

 dale at least two, j)erhaps three, weeks later. Further observations, 

 however, are needed on the exact time of appearance in a normal year, 

 since the i)ast two summers (1908 and 1909) in which this species has 

 been studied, have been unusu.illy backward in .Southern Michigan. 

 While the difference in latitude might account for a slight difference in the 

 dates of appearance, it should be noted that the conditions which the bogs 

 present to the butterflies, at least in the vegetation and low temperature, 

 are probably little different north or south in the State, for the bogs in 

 Southern Michi^^an preserve their boreal character, although set in more 

 southern surroundings. 



Until We found them at \Vaucedah, our search for iht/ruticosa and 

 Jorcits had been confined to the country about Brown 1-ake, practically 

 entirely away from the inroads of ciCili/ation. Apparently very favourable 

 localities existed for the plant about the margins of the bogs and lakes in 

 that region, but it could not be found. I mention this, as it would seem 

 that Dasiphora /ntticosa and its tenant i/ofnis can enter such regions 

 only after the latter have been altered by man, or that considerable open 

 areas (natural or artificial) about the borders of bogs, etc., are necessary 

 for the successful establishment of this shrub. 



I was able to make only one other short trip to the NVaucedah 

 habitat on the ninth of August. The condition of the females, still bright 

 and fresh and more numerous than five days before, two pairs in copula- 

 tion and only slight evidence of oviposition (only two eggs having been 

 found on a large lot oi/mticosn), emphasized the late flight of the species. 



Si.xty females were collected, and I find that the most noticeable 

 difference between this scries of females and those taken in .Southern 

 Michigan lies in the predominant amount of yellow in the northern ones 

 (iorm /forus). There is not a specimen in the lot that does not show an 

 indication of yellow, while in about one-fourth of them it is conspicuous in 

 a nearly complete band adjacent to the outer side of the transverse row 

 of black spots. In the others there are various gradations in the amount 

 of yellow down to an almost entire absence of that colour. This is in 



