36 UNITED STATES NATIONAL MUSEUM BULLETIN 2 76 



Five major components make up the forewing pattern. They are the 

 inner, median, and outer areas, and the inner and outer lines (fig. 10). 

 The median area and the inner and outer lines together may form what 

 can be called a median band if they are similarly colored as in figure 

 120. 



Just proximal to the inner line and just distal to the outer line are 

 narrow areas paralleling the inner and outer lines which may be 

 distinctly lighter than the remainder of the inner and outer areas or 

 the median area of the wing. Sometimes the median part of the median 

 area is lighter than the edges of the area, resulting in the darker 

 edges appearing as a pair of dark lines set off by the lighter n^edian 

 part and the narrow lighter areas paralleling the inner and outer 

 lines as in figure 249. In contrast, when the median band is the same 

 color as the outer and inner areas of the wing, the wing may appear 

 to be crossed by a pair of light lines formed by the narrow lighter 

 areas paralleling the inner and outer lines as in figure 250. All of 

 these components of the color pattern may vary from light to dark, 

 and different combinations may result in strikingly different appear- 

 ances of individual moths from the same populations or even the same 

 colonies. 



In some species such as M. americanum (figs. 312-320), the lines 

 are invariably lighter than the surrounding areas. In other species 

 such as M. disstria (figs. 119-139) the lines are invariably darker, 

 but they may be bordered by faint lighter areas as in figure 127. In 

 other species such as M. constrictum the lines usually are dark, but 

 strikingly different individuals may be found in the same locality 

 (compare figs. 155-156). In some species, however, especially M. 

 californicum and M. incurvum, the components of the wing pattern 

 are even more highly variable and almost exact opposites in patterns 

 may be found (compare fig. 225 with 227, 249 with 250, 256 with 258, 

 285 with 287, and 295 with 304). Because of these extreme variations 

 and the many other variations found in adult Malacosorna, individuals 

 showing many of these variations have been illustrated for all species 

 and subspecies. 



The outer margin of the forewings is usually fringed with alter- 

 nating patches of light and dark scales as in figure 204, but some 

 specimens may have a unicolorous fringe as in figure 214 or 285. 

 Ventrally (fig. 311), the forewing has only a single line in approxi- 

 mately the same position as the outer line on the upper surface. 



Dorsally, the hindwing is usually uniformly colored, but sometimes 

 has a contrasting light or dark transverse area which approximately 

 lines up with the outer line of the forewing on spread specimens as 

 in figures 162, 179, 270, and 278. Ventrally, the hindwing (fig. 311) 



