ART. 2 REVISIOlSr OF TEIEHABDA NORTH OF MEXICO BLAKE 15 



dark, usually with only margin of metasternum and abdomen dark. 

 Length, 6 mm. to 10 mm. ; width, 2.8 mm. to 4.5 mm. 



Type. — Collected by E. R. Kalmbach, July, August, 1912, at 

 Bountiful, Utah. U. S. N. M. No. 43016 (with 11 paratypes). 



Distribution. — " Hudson's Bay Territory," Illinois, Maryland, 

 North Dakota, South Dakota, Kansas, Missouri, Texas, Wyoming, 

 Montana, Utah, Nevada, California. 



Food plants. — Thistle, Cirsium sp. (I. N. Gabrielson, North 

 Dakota) ; tall goldenrod, Solidago altissima (J. C. Bridwell, Glen 

 Echo, Montgomery County, Md., near Washington, D. C). 



Remarks. — This species has always been confused with canadensis^ 

 which it closely resembles in size and general coloring. There are 

 structural differences, however, in the shape of the tip of the 

 aedeagus, besides the difference in the shape of the prothorax, with 

 its more arcuate sides. The markings are also slightly different. 

 There is a much wider basal plaga across the head, the pronotal 

 spots are larger and rounder, and the elytral vittae do not ordinarily 

 unite at the apex of the elytra as in canadensis. The elytra, too, are 

 a little more coarsely punctate. 



It has been collected chiefly west of the Mississippi River, although 

 a large series from Illinois is in the collection of the Illinois State 

 Natural History Survey, and a series was taken by J. C. Bridwell in 

 the Potomac River Valley at Glen Echo, Md. 



Specimens of this species in Blanchard's collection are labeled by 

 him as " western canadensis.'''' 



4. TRIRHABDA VIRGATA LeConte 



Plate 1, Figure 4 



TrirhaMa rirgata LeConte, Proc. Acad. Nat. Sci. Philadelphia, vol. 17, p. 220, 

 1865. 



Description. — Oblong, robust, coarsely punctate, pale with dark- 

 ened antennae, with black occipital spot, three moderately large 

 pronotal spots, and wide piceous lateral and sutural vittae, usually 

 not united at apex. Head alutaceous with obsolete coarse punctures ; 

 usually a wide, oblong, black occipital spot extending down front and 

 covering base of head (shown when head is protruded) ; sparsely 

 pubescent. Antennae robust, with third joint much shorter than 

 fifth. Prothorax approximately twice as broad as long, usually ob- 

 tusel}' angulate ; surface dull and strongly alutaceous with scattered, 

 coarse, shallow punctures; spots moderately large. Scutellum en- 

 tirely black. Elytra coarsely and confluently punctate, inconspic- 

 uously and rather sparsely pubescent ; lateral and sutural vittae wide, 

 the former usually wider than inclosed pale vitta, these dark vittae 



