EVOLUTION OF COLOR PATTERN IN LITHOCOLLETIS. 139 



scales of the apex, those between the two parts of Band IV and in the angle of 

 Band III. are darker than the other scales forming the margins. 



In a specimen at a considerably more advanced stage of development, the 

 scales composing the two patches at the base of the costa are entirely gray tipped 

 and very much the same as they will appear in the adult. The colorless scales 

 mingled with those forming the proximal part of Band II are beginning to be 

 gray tipped; this is especially noticeable on the quadrate part above the upper 

 median vein; below it, there is only a line of a few scattered gray tipped scales 

 reaching to the dorsum. The line of scales beyond, forming the original outer 

 limit to Band II, is pale gray tipped throughout and, though broader on the costa, 

 is complete to the dorsum. The broadening of the internal margin of Band III 

 has continued. Its external margin, separated from the yellow band by white, 

 is indicated by a single line of pale gray tipped scales running from the costa to 

 the cell. The internal margin of Band IV has broadened and deepened and has 

 now probably reached its adult condition. It is not possible to determine 

 whether the development is completed in any single specimen, since there is a 

 great deal of variation in the amount of dusting among the different individuals 

 in this species. In this stage, the scales which in the imago are the most distal 

 of those forming the dark external margin of Band IV are tipped with pale gray 

 and connect with the dusting between the costal and dorsal parts of Band IV. 

 Those on the inner side of the margin which will in a great measure fill up the 

 white space between the margin and the yellow parts of the band are still un- 

 colored. There is a very considerable patch of dusting internal to Band V + VI 

 on the dorsal margin and connected with the apical dusting which has been 



IV 



V+VI 



extended proximally between the parts of V + VI. ri l^~ „ ,.,, 



The costal dusting is not nearly as dark and is some- ^-"^^^^"^ ^f^^^. 



what scattered. In addition to the extension of the 



apical dusting proximally, there has been an increase 



in the number of dark scales mingled with the cilia. Fig. 23. Wing of l. immadry- 



The dark line through the middle of the cilia formed ^^'"^ ^^^^ ^^^ ^^^ ^^ ^^^ p^p^^ 



state 



by brown tipped yellow scales is now quite distinct. 



At this time, most of the dark markings are at least definitely defined in posi- 

 tion; there is needed to bring them to their final state only a darkening of those 

 scales already gray tipped and in some places the appearance of pigment in 

 other scales adjacent to these. 



In a specimen to be described now, most of these characters have appeared 

 {Fig. 23). The patches of dark gray scales at the base of the costa and the hne 

 of scales beyond the third of these patches have increased and darkened decidedly. 

 The line of scales external to Band III has now become dark gray tipped. Ex- 

 ternal to Band IV, the dusting has been extended toward the base, so that only 

 a small white streak is left between it and the band on the margins. The dusting 

 in the apex has been much increased and extends along the margin, especially on 

 the costa, and connects with the internal dusting of Band V, thus almost obhter- 

 ating the white streak over vein 7. 



