REVISION MALACOSOMA HUBNER IN NORTH AMERICA 75 



part of the Great Basin (fig. 2) ; specimens may be found farther 

 south in California and in Mexico, too. 



calif or nicum fragile, p. 164 

 Color not as above, usually more orange-brown, yellow-brown 

 or gray-brown; lines on forewings with or without indenta- 

 tions along veins; distribution — western and northern North 

 America, but not from the Mojave Desert area outlined above 



except along streams or irrigated areas 7 



7(6). Color usually medium brown to somewhat blackish-brown, 

 often with median area of forewings somewhat darker than 

 inner or outer areas; lines on forewings usually rather sub- 

 dued and forming a border for the darker median area if one 

 is present; indentations along veins, if present, usually small 

 (figs. 289, 293, and 296). 

 Distribution — usually along watercourses in central and 



southern Arizona incurvum incurvum, p. 173 



Distribution — the Mexican plateau area as presently known. 



incurvum aztecwn, p. 183 

 Color variable, but usually more yellow, orange-brown, or 

 gray-brown; median area variable; lines on forewings dark 

 or light, usually distinct; indentations along veins present 

 or absent ; distribution — most of western and northern North 

 America, but not known from the Mexican plateau area yet, 

 and rare along watercourses in central and southern 



Arizona 8 



8(7). Color a soft yellowish or orange-gray-brown; lines on fore- 

 wings usually rather evenly curved (figs. 302, 305, and 308), 

 with only a few small indentations along veins, if any, and 

 usually with lines not sharply contrasting with background 

 color as in figure 305 ; distribution — lower parts of Colorado 

 River and its tributaries above Hoover Dam (fig. 4) . 



incurvum discoloratum, p. 177 



Color variable, but in the distributional area outlined above, 



usually more orange-brown with more sharply contrasting 



lines on forewings; indentations along veins varying from 



small to quite "jagged" californicum 9 



9(8). Lines on forewings usually appearing dark on a yellowish or 

 yellow-orange-brown background as in figure 180, but 

 appearing light if the background is darker than normal 

 as in figure 181; dorsal lobe of ovipositor usually somewhat 

 reduced as in figure 98; distribution — California, Oregon, 

 Washington, Idaho, western Montana, British Columbia, 



279-280—68 6 



