BUTTERFLIES OF THE DISTRICT OF COLUMBIA 161 



The females are more variable than the males. Although as a rule 

 the hind wings of the females are broader and more evenly rounded 

 than those of the males, they occasionally have the same form, or 

 perhaps more correctly the form of the hind wings seen in the 

 female of Zerene caesonia, with a well-developed rounded angle at 

 the end of the upper radial and a well-developed rounded anal 

 angle. The angle between the inner and outer border of the fore 

 wings is ordinarily obtuse, somewhat less so than in the male, more 

 rarely a right angle. Rarely females have the hind wings broadly 

 and evenly rounded and the fore wings rather strongly convex on 

 the outer margin. 



The black border on the fore wings is usually heavy, the black 

 extending inward for two-thirds of the distance from the apex of 

 the wings to the cell spot. The spots within this border are very 

 variable in size. Occasionally they are wholly absent, the margin 

 of the wing both in the yellow and in the white form being solid 

 black. Sometimes the black border is narrow and of uniform width, 

 not broadening toward the apex, so that it extends less than half the 

 distance from the apex to the black spot. The border of the hind 

 wings is very variable, though usually broad and rather heavy. Its 

 upper portion may inclose a rather large rounded yellow (or white) 

 spot, and sometimes it may more or less completely inclose another 

 below it ; usually the first of these is more or less definitely indicated. 

 Beneath these spots the dark scaling usually runs up the veins in a 

 short tooth, more rarely the inner border of the black margin is 

 smooth. Occasionally the margin is reduced to a series of curved tri- 

 angles with their broad bases, which are separated from one another 

 by narrow yellow (or white) lines, situated on the margin of the wing 

 and their produced and attenuated inner apices running inward 

 along the veins. In extreme cases the bases of the triangles may be 

 very narrow and widely separated and the black may run for a long 

 distance inward along the veins, especially the two uppermost, as a 

 black line. When the black on the fore wings is much reduced there 

 may be simply a light dusting of dark scales on the ends of the four 

 anterior veins. In some individuals, both yellow and white, the 

 base of the fore wings as far as a line at right angles to the inner 

 border passing through the origin of vein Mi is very heavily dusted 

 with deep olive (in the yellow individuals) or dark gray (in the 

 white) scales, and similar scales are also abundant on the abdominal 

 half of the hind wings, especially toward the base. 



In both sexes there is great variation in the color of the spot at the 

 end of the cell in the hind wings. It is usually bright orange, but is 

 sometimes so pale as scarcely to 1be distinguished against the ground 

 color of the wings, or it may be deep reddish orange, almost as bright 



