EVOLUTION OF COLOR PATTERN IN LITHOCOLLETIS. 133 
of the wing below the fold, to be occupied by black scales in the adult, is pale 
gray; beyond the fascia where the scales are merely brown tipped, the color is 
still yellow, concolorous with the rest of the wing. Internal and external margins 
of the streaks are beginning to form simultaneously, 
those of the first costal streak are the deepest. The — 
change is direct from the colorless scales margining the p = е; 
white streaks to pale gray. "The black streak in the fold aS im^ 
beyond the fascia is at this stage composed of pale gray Fio. 17. Later stage in the 
scales. The apical dot is still pale gray, but the outer- И — ai a 
most row of scales is much darker and continuous on 
either side with a line of gray scales extending from the fourth costal streak 
to the third dorsal streak. The scales whose tips are to form the dark line in 
the cilia are still white. 
On the next wing examined, the gray has decidedly deepened along the dorsal 
margin, but the golden color has not reached its final condition. The develop- 
ment of the margins has progressed considerably, but now the internal are 
decidedly in advance of the external margins. The former have a blackish color, 
especially toward the costal margin; the latter are still grayish. The external 
margin of the first costal streak is deeper than that of the others. The black 
streak in the fold has practically reached its adult condition. The apical dot 
has increased in size and color until its extent is now definitely defined. The 
scales around its outer edge, which in the preceding stage were the only dark 
ones, are now black. The line in the cilia is gray, but there is no indication of 
the bluish iridescence. 
From this time on, no new characters appear, the development consisting 
only of a deepening of the colors to their adult condition. 
The sequence of colors and the relative time of appearance of the various 
adult characters is very much the same in L. robiniella as in the species just 
studied. The apical spot and the black streak in the fold reach their final 
condition at a somewhat earlier stage in comparison with the development of 
the other markings. 
т w 
= 
Lithocolletis hageni F. and В. 
This species (Fig. 17, Pl. III) possesses a well-defined apical dot, very decided 
external margins to the white streaks as well as the usual internal ones and a 
dark margin along the upper side of the basal streak. The margin along the 
upper side of the white basal patch is regarded as homologous with the margin 
of a basal streak, that along its outer side with the external margin of the white 
streak primitively separating Bands II and III. The streak of ground color 
beyond the basal white patch is, therefore, the dorsal portion of Band III. 
Very few specimens of this species were available for study, but the obser- 
vations confirm in general those made upon the five preceding species. 
The apical dot appears well-defined and blackish at a period when Bands 
