EVOLUTION OF COLOR PATTERN IN LITHOCOLLETIS. 131 
ment, there are four dorsal as well as four costal streaks. The apical dot is 
present, dark brown and almost as large as in the imago and very definitely 
outlined. Around the extreme apex, the scales projecting into the cilia are 
tipped with brown, this color being deepest just opposite the apical dot but 
quickly fading out on either side, so that it does not reach to the last pair of 
white streaks. "The apical spot and these few scales around the apex are the 
only seales on the wing which show the slightest sign of brown; the bands are, 
however, a little deeper yellow on their outer than on their inner borders. 
Very soon after the stage just described, the dark margin of the second dorsal 
streak begins to develop; at this time, it consists of a few darker and slightly gray- 
ish tinted scales somewhat removed from the dorsal margin. The apical spot 
is brownish black and seems to have reached its final development. The line 
in the cilia, though darkest immediately opposite the apical spot, is plainly visible 
from the fourth costal to the third dorsal streak, thus passing below the fourth 
dorsal streak which at this stage has almost disappeared owing to the fusion of 
Bands VI and VII. | 
Very little change is now needed to reach the adult condition. The margins 
of the second pair of white streaks continue somewhat in advance of the others 
and reach their final stage of development a little earlier. All trace of a fourth 
dorsal streak finally disappears. 
Lithocolletis lucidicostella Clem. 
At the time of the first appearance of a pale yellow tinge upon the wings, 
it is possible to discern faintly four bands in the apical half of the wing. Just 
before the apex within the area occupied by Band VII is a small colorless spot. 
With the exception of the fact that these four bands are not connected along the 
middle of the wing, the adult color areas (Fig. 44, Pl. III) are now laid down. 
The dorsal portion of Band IV, the most proximal of these four bands, is con- 
tinued toward the base, as in the adult, by a pale yellow streak along the fold. 
Its costal portion is preceded by a white streak bordered internally by pale 
yellow which is extended along the upper median vein to the base. 
The apical dot is the first dark mark to make its appearance. While the 
yellow is still very pale, the scales of the formerly colorless spot near the apex 
begin to take on a grayish tinge. The deepening of scales over this area seems 
to take place in very much the same manner as that of the dark scales before the 
apex in L. cratagella. 
The apical spot continues to deepen and increase in extent, reaching its 
adult condition before there is any indication of the formation of dark margins. 
The development of the apical spot is accompanied by a gradual and uniform 
deepening of the ground color together with the fusion of all the bands in the 
middle of the wing and of VI and VII on the termen. The middle portions of 
the wing between the apices of the white spots are somewhat paler, showing 
where the pigment has recently appeared. 
