160 BULLETIN 15 7, U. S. NATIONAL MUSEUM 



mon, and fresh females appear. They do not become abundant, how- 

 ever, until the last week in June, when, usually shortly before the 

 first of July, their numbers suddenly increase. The butterflies con- 

 tinue abundant into early August, when fresh individuals again 

 grow scarce. Just before the middle of August males of the third 

 brood appear, flying with the still numerous individuals of the second 

 brood. The third brood becomes exceedingly abundant at the last of 

 August and in the first week in September, and continues to fly in 

 numbers, with the constant addition of fresh individuals, until at 

 least about the middle and usually about the end of October. 



Notes. — The early-spring females at hand are all very small, 

 with the fore wings only 24 or 25 mm. in length. In most of them 

 the dark border of the hind wings is narrow with a slightly scalloped 

 inner border, which in some shows a slight tendency to continue 

 inward along the anterior veins. It may terminate just after vein 

 Ma, or it may be continued somewhat farther. In a white female 

 taken in April it is rather broad and is continued as a haze of dark 

 scales almost to the anal angle. The dark border on the fore wings 

 is narrow, the portion below vein Ms being about as wide as the 

 cell, with the included spots separated from the yellow of the wing 

 only by a fine hazy line, or sometimes not at all. In two white 

 females this border is somewhat broader and the apical portion is 

 extended inward for about two-thirds of the distance from the apex 

 to the black spot, while the included spots are much reduced in size. 

 A yellow female also has the apical portion of the border extended 

 inward in the same way and the included spots much reduced. In 

 this individual the black spot at the end of the cell has a conspicuous 

 yellow center. 



In these early individuals the hind wings are broadly and evenly 

 rounded, and the fore wings are rather short with the outer border 

 always more or less convex and the apex well rounded. 



The later individuals of this brood are larger than the earlier and 

 resemble the individuals of the brood following. 



The males of the second brood vary very little. Most of the 

 variation is in the shape of the hind wings, the relative development 

 of the broadly rounded angle at the end of the upper radial, which 

 may be wholly wanting, and the relative development of the anal 

 angle, which occasionally is so very broadly rounded as to be 

 almost absent. From time to time enormous individuals, abruptly 

 larger than the largest ordinarily found, are seen. These are wary 

 and very strong fliers and act more like the males of C. eurytheme 

 than like the smaller males of their own species. Theyi seem to be 

 representatives of the form occurring in the Mississippi Valley and 

 in the valleys of West Virginia and western Virginia. 



