80 UNITED STATES NATIONAL MUSEUM BULLETIN 276 



( ! !) as in incur vum incurvum; never with a vertical black bar; 

 lateral setae white or golden orange and tufted ; dorsal setae 

 golden; lateral color usually black and bluish-gray (speci- 

 mens which have been examined are most similar to figs. 

 391 and 394); occurring in the Mexican plateau area. 



most incurvum aztecum, p. 183 

 10c(9). Lateral setae white and not conspicuously tufted; lateral 

 areas bluish and never with a vertical black bar; setae SDl 

 and SD2 usually white, sometimes dark; addorsal area 

 usually with some orange (fig. 399); occurring mainly at 

 lower elevations along the Colorado River and its tribu- 

 taries above Hoover Dam. 



rare specimens oi incurvum discoloratum, p. 177 

 10d(9). Middorsal and addorsal areas usually black (fig. 382) with 

 the addorsal orange markings, if present, usually reduced; 

 lateral color bluish, occasionally with a vertical black 

 bar (fig. 387); lateral setae white, yellowish, or orange 

 and not tufted or only slightly so; occurring primarily 

 at higher elevations in northern and eastern Arizona, 

 and in the Great Basin and southern Rocky Mountains, but 

 occurring at lower elevations if suitable hosts are present; 

 not known to occur in the central plateau around Mexico 

 City, but possibly found in the area between Mexico City 

 and United States border. 



calif ornicum (in part), p. 123 

 11(3). Lateral setae white and not conspicuously tufted; lateral 

 area bluish and never with a vertical black bar; middorsal 

 stripe bluish-white, often about the same color as the sub- 

 dorsal area (figs. 395-397), but whiter on some specimens 

 (fig. 398); setae SDl and SD2 usually white; occurring 

 mainly at lower elevations along the Colorado River and its 

 tributaries above Hoover Dam. 



most incurvum discoloratum, p. 177 



Various combinations of characters; occurring throughout 



western North America, but if occurring at lower elevations 



along the Colorado River and its tributaries above Hoover 



Dam, setae SDl and SD2 are usually black 12 



12(1 1). Addorsal areas usually with some indistinct orange markings; 

 subdorsal area blackish; supraspiracular area bluish-gray; 

 subspiracular area bluish-gray and whitish; dorsal setae 

 golden orange; lateral setae white or golden orange (like 

 figs. 390-394, but with weak dorsal stripe); occurring 

 mainly at lower elevations in central and southern Arizona, 

 primarily along watercourses and irrigated areas, but ex- 



