EVOLUTION OF COLOR PATTERN IN LITHOCOLLETIS. 137 
In the next stage studied, the color has become almost as deep as in the 
adult. A number of the scales projecting from the extreme tip of the wing over 
the eilia are brown tipped; these are continued in a broken line through the cilia 
to the tornus. Over the wing membrane near the apex, in the area which was 
transparent in the earlier specimen, the scales are becoming dark tipped. These 
scales are deepest toward the apex of the wing, becoming very pale gray toward 
the tornus external to the oblique dorsal streak. A few scales along the costa 
corresponding in position with the dark scales in the adult are beginning to show 
darker tips. The scales margining the first and second costal streaks, which were 
. whitish before, are now faintly gray. Тһе color is uniformly developed over the 
whole margin and on the prolonged portion of the second streak. 
In a specimen a little further advanced than the one just described, the apical 
dusting is almost as in the adult. This darker color does not quite reach the 
tornus; that is, the external edge of the white dorsal streak is still margined by 
pale gray scales as before. The margins of the first and second costal streaks 
have scarcely changed in color, but the scales in the prolonged portion of the 
second streak have darkened more rapidly; they are decidedly gray but much 
paler than those in the apex. The only new character which has appeared is 
the dark line through the cilia. 
Lithocolletis hamadryadella Clem. 
In the earliest stage examined (Fig. 21), the basal third of the wing is almost 
colorless. At the extreme base on the costal margin is a small patch of pale 
yellow scales, and a little beyond it another similar patch. These two patches 
of scales form Band I. Beyond these is a somewhat larger patch of pale yellow 
scales. This is the inner portion of Band II; the line of scales which marks its 
original outer limit in the adult (Fig. 77, Pl. IV) has not yet acquired any pig- 
ment. Band П at this stage is represented by a rather narrow angulated band 
which extends across the wing some distance before the tip of vein 1b. The 
white projects into its angle on the inner side. Band IV is composed of two 
separate patches of yellow scales, one on the costa and the other on the dorsum. 
Their pointed apices lie over the bases of veins 10 and 
2 respectively, the normal position for Band IV, but 
on the margins, they eurve back toward the base so 
that they are much farther removed from the tips of 
the veins than usual. The middle of the wing to the ^ 
apex is colorless. Вапа V + VI is represented by a Ёс. 21. Early stage in the 
: . development of color in the wing 
patch of scales on either margin. The dorsal patch бү. studeo vem 
originates just beyond vein 2 and extends over vein 
5; the costal patch originates on the cell about midway between veins 10 and 
9 but extends obliquely outward so that the inner edge on the costa is just basal 
to vein 9 and the outer edge just before vein 7. The white streak over the tip of 
vein 7 is very narrow, and its corresponding dorsal streak is indistinct. The 
