22 PROCEEDINGS OF THE NATIONAL MUSEUM vol.70 



tate, moderately pubescent, surface somewhat shining. Vittae 

 bright blue-green or blue, wide, usually coalescing at or behind 

 middle, leaving a pale vitta wider at base and becoming attenuated 

 toward apex, occasionally the pale vitta extending nearly to apex, 

 but sutural and lateral vittae always united. Body beneath pale 

 with metasternum and sides of abdomen dark with metallic luster, 

 densely covered with white pubescence. Length, 5 mm. to 8 mm.; 

 width, 2 mm. to 3.8 mm. 



Type Zoca?^^2/•— Collected by T. Nuttall " in Mississippi " (on the 

 Mississippi ? ) . 



Distrlhution. — South Dakota (Black Hills, Dewey, Fall River 

 County, Hat Creek) ; Nebraska (Hat Creek) ; Kansas (Cheyenne 

 County) ; Montana (Poplar, Musselshell County, Meagher County, 

 Huntley, Gallatin Mountains, Assiniboine, Glendive) ; Wyoming 

 (Platte County); Colorado (Eckley, Morrison); Utah; Alberta 

 (Medicine Hat) ; British Columbia. 



F'ood plants. — Sagebrush, Arte?7iisia, and goldenrod, Solidago (F. 

 S. Carr). 



Remarks. — Say's name attenuata., based on specimens " captured by 

 Mr. Nuttall in Mississippi," was adopted by LeConte for this species, 

 although Say's description of the elytra as polished does not fit 

 either this or any other Trirlidbda. The elytra are somewhat shining 

 with metallic luster and are very finely punctate. The type locality, 

 also, seems somewhat doubtful; I have seen no specimens taken 

 east of the Dakotas, Nebraska, and Kansas. Possibly Nuttall col- 

 lected it along the Mississippi or its branches. 



11. TRIRHABDA LEWISII Crotch 



Plate 1, Figure 11 



Trihahda (sic) levnsii Ceotch, Proc. Acad. Nat. Sci. Philadelphia, vol. 25, p. 56, 



1873. 

 TrirhaMa lewisii Horn, Trans. Amer. Eut. Soc, vol. 20, p. 70, 1893. 



DescHption. — Of moderate size, elongate, parallel, lightly punc- 

 tate and pubescent; pale yellow with wide black plaga across occi- 

 put, moderate-sized black pronotal spots, elytra with moderately 

 wide lateral and sutural vittae, green, blue, purple, or piceous, these 

 vittae usually united at apex. Head alutaceous with obsolete, shal- 

 low, coarse punctures over occiput, lightly pubescent; a wide black 

 plaga extending across base of head and curving widely over front. 

 Antennae with third and fifth joints subequal. Prothorax fully 

 twice as broad as long with arcuate sides, surface not shining, aluta- 

 ceous with scattered coarse punctures; spots moderately large. 

 Scutellum bicolored. Elytra lightly punctate, pubescence short and 

 inconspicuous; a moderately wide lateral and sutural vitta, usually 



