126 EVOLUTION OF COLOR PATTERN IN LITHOCOLLETIS. 



short distance onto the wing proper. The middle of Band IV is faintly con- 

 nected with a pale band beyond, which represents Band V. Its margins have 

 reached more nearly their adult condition than any other of the wing markings. 

 The margin on the dorsal half is almost as greatly developed as in the adult; 

 that on the costal half is represented only by a few black scales. 



The next stage studied shows no further change in the shape or extent of 

 an}^ of the bands, the changes which have taken place being confined to continu- 

 ation of processes already begun, namely, the deepening of the outer edge of 

 Band II, thus forming the internal margin of the first white fascia in the adult, 

 the approximation of the costal and dorsal parts of the margin of Band III, so 

 that they are now but little separated, and their darkening to the adult color, 

 the advance of the margins of Band IV to their adult condition, the deepening 

 of Band V so that it now appears quite distinct and as in the adult. 



This is the only species studied which shows any distinction between the 

 bands in regard to their relative time of appearance. Bands II, III and IV are 

 the first to appear, and in the youngest specimen examined, Band IV was de- 

 cidedly in advance of the other two as shown by its deeper color and by its 

 extension outwardly in the middle. It is, therefore, probably safe to assume that 

 Band IV is in this species, the earliest to appear ontogenetically. As will be 

 shown later, L. tiliacella has probably in many respects conserved more closely 

 than any other of the now existing species the primitive type of color pattern, 

 and hence the sequence observed in the appearance of the bands in the ontogeny 

 may also be true for the phylogeny. 



Lithocolletis tritaenianella Cham. 



At the earliest stage at which it is possible to discern any indication of 

 marking, five very pale yellow bands are visible upon the wing {Fig. 11). These 



are uniformly colored and straight and are placed trans- 



^^' versely upon the wing, showing no signs of fusion with 



J one another. The first of these is, in fact, I + II, as 



shown by the faintly paler streak extending into it from 



Fig. 11. Early stage in the the basc of the dorsum. The sccond. Band III, occu- 



deveiopment of color in the pj^g j^g ^g^^j positiou, but in this casc the position of 



wing of L. iriioenianella. ,. p. . .^ tx* inij 



the white lascia separating it from II is wholly deter- 

 mined by the point of origin of the upper median vein, as vein 12 extends for a con- 

 siderable distance into Band III. The third, Band IV, is normal in position and 

 shape. That the fourth band is in reality composed of Bands V and VI is shown 

 by its origin just beyond the tips of veins 10 and 2 and by its extension distally 

 over the tips of 9 and 5 which in the primitive color pattern mark the position 

 of the white fascia separating Bands V and VI. Band VII crosses the apex of 

 the wing. The white interspaces between Bands II and III and between III 

 and IV are of about the same width as in the adult, but that between IV and 

 V + VI is considerably wider and shows no indication of the angulation which 



