70 UNITED STATES NATIONAL MUSEUM BULLETIN 2 76 



variation in color between the areas; color extremely 

 variable, ranging from gray to brown to yellow to orange- 

 brown and various intermediate shades (see males in figs. 

 176-308 except figs. 206-208); genitalia not as in figures 

 14, 32, 39, and 59; distribution — all of western and northern 



North America 6 



6(1, 5). Lines on forewing white or y ellowish- white ; outer line often 

 nearly straight as in figure 314, and without indentations 

 along the veins; lines never appearing to be bordered by a 

 darker line; genitalia as in figures 15, 30, 31, 40, and 60; 

 total length of eighth sternite (fig. 40) almost always 

 distinctly greater than length of fore tibia ; distribution — 

 east of the central Great Plains and south from southern 

 Canada to the Gulf of Mexico (fig. 2). 



americanum, p. 1 1 1 



Lines on forewing dark or light, lines various shades of yellow, 

 orange, white, brown and gray; outer line usually distinctly 

 bowed outward as in figure 295, and often with indentations 

 along the veins as in figure 297; lines sometimes appearing 

 to be bordered by a darker line as in figure 264; genitalia 

 not as in figures 15, 30, 31, 40, and 60; total length of eighth 

 sternite (figs. 41-51) almost always distinctly less than 

 length of fore tibia ; distribution — west of the central Great 

 Plains, the northern edge of the United States, and 



Canada 7 



7(6)*. Both forewings and hindwings usually dark reddish-brown; 

 dark lines (sometimes very faint) crossing forewings which 

 usually are not bordered by a light narrow area (figs. 188 

 and 189); distribution — west side of the Sierra Nevada and 

 parts of northern California (fig. 3). 



californicum recenseo, p. 148 



Forewings and hindwings variable in color, sometimes dark 

 reddish-brown, but usually a dark orange-brown, gray- 

 brown, yellow-brown, or variations thereof; lines on fore- 

 wings appearing light or dark, but usually bordered by a 

 contrasting, narrow area (males in figs. 1 76-308 except figs. 

 188, 189, and 206-208); distribution— western North 



America except the area listed above 8 



8(7). Color of wings usually mixed gray- white and chocolate-brown, 

 sometimes with a yellowish tint, especially in specimens from 



*There are no known structural characters which will separate the two species 

 and their subspecies which make up the rest of this key. In some cases the subspecies 

 are recognized on the basis of larval differences, but no matter what characters are 

 used, it is not possible to identify some specimens. 



