AMERICAN COLEOPTERA. 47 



turn flat posteriorly, moderately declivous from about the anterior two 

 fifths, margin of declivity raised and bearing about five erect setae. 

 Head rather closely not coarsely punctate, clypeus sinuate at middle 

 with broadly rounded angles; suture posteriorly arcuate at middle, 

 the adjacent surface of the front smoother; post-clypeal elevation and 

 frontal impressions feeble but usually quite evident. Prothorax very 

 nearly twice as wide as long, sides parallel or a little convergent in 

 posterior half, more strongly convergent in front, hind angles slightly 

 obtuse, front angles feebly prominent; punctuation moderately close, 

 the punctures separated by about their own diameters at the middle, 

 closer at sides; all the angles impressed. Elytra three-fourths as wide 

 as long and slightly more than three times the length of the prothorax; 

 discal costse distinctly defined but scarcely at all elevated; intercostal 

 areas with rather sparse confused punctuation, the first fully three times 

 as wide as the sutural interval, the second about two-thirds as wide as 

 the first. Punctuation beneath fine and sparse at middle, coarser and 

 closer but not dense at sides. Upper tooth of front tibia? submedian 

 in position, perhaps a trifle nearer the apex than the base. Hind 

 thighs very sparsely finely punctate at middle. Ungual tooth sub- 

 apical, its tip nearly or quite twice as distant from the base as from 

 the apex of the claw. Length 9.6-12.2 mm. 



The range of this species is nearly identical with that of 

 brevicollis, though extending somewhat further to the north. 

 Obscura is indeed more common in the northern part of its 

 range, while the reverse seems to be true of brevicollis. The 

 type was taken in the Black Hills (Dakota) by Dr. Ham- 

 mond. I have seen specimens from Colorado Springs, Empire 

 and Georgetown, Colorado; Sheridan, Wyoming; Helena and 

 Assiniboine, Montana; Alta, Utah; Williams, Arizona; Pull- 

 man and Spokane, Washington; Vernon, British Columbia; 

 Oxbow, Saskatchawan ; Calgary, Alberta; together with num- 

 erous specimens representing nearly all of these States, but 

 without indication of exact locality. 



In a species so widely dispersed, a considerable amount of 

 variation is to be expected. Two forms, which I regard as 

 races of this species, seem to me to merit distinctive names. 

 Intermediates between these and the typical form have been 

 seen, but unles sthese are at hand, the collector might easily 

 be persuaded that he had to do with three distinct species. 



Var. prominens n. var. — Differs from the typical form in 

 being more elongate, with sides of prothorax less rounded and 



TRANS. AM. ENT. SOC, XXXV. FEBRUARY, 1909. 



