54 AMERICAN COLEOPTERA. 



seneous, the first rarely rufous beneath. Prothorax nearly twice as wide as long, 

 distinctly narrower at base than apex, more or less transversely wrinkled along 

 the median line, rugose at base ; apex emarginate; median line distinct, extend- 

 ing between the transverse impressions, which are distinct; basal impressions 

 broad, moderately deep ; sides with the margin narrowly reflexed, strongly ar- 

 cuate, sinuate for a short distance in front of the hind angles, which are obtuse, 

 but not rounded. Elytra about one-half wider than the thorax, oblong-ovate, 

 finely striate, more finely towards the tip ; strife distinctly punctate to behind 

 the middle, the third with the dorsal punctures large, round, foveiform, the first 

 about the middle, the second about one-fourth from apex ; intervals flat or nearly 

 so. Beneath greenish black, shining. Legs aeneo-piceous. the femora sometimes 

 more or less rufous at base. Length .27-.30 inch : 6.75-7.5 mm. 



The largest species of the group. It is most nearly allied to 

 americanum, from which it differs by its larger size, more depressed 

 form and proportionally wider thorax, which is more narrowed be- 

 hind, with the sides more strongly arcuate. The elytra are usually 

 more coarsely alutaceous, especially at the sides, the amount of shin- 

 ing surface being often confined to the three or four inner intervals. 

 This is, however, subject to some variation. 



It occurs from the Rocky Mountain region westward to the Pacific 

 coast. Specimens have been seen from Nebraska, Kansas, Wyoming, 

 Colorado, Texas, New Mexico, Utah, California, Oregon, Washing- 

 ton, British Columbia and Vancouver Island. 



16. B. americanum Dej. — Form moderately broad, slightly depressed; 

 color seneous, more or less coppery, shiuin'g. Head as wide as the thorax at apex, 

 alutaceous, subopaque ; palpi rufo-piceous. slightly paler at base : antennpe about 

 one-half the length of the body, piceous. the first joint and sometimes the second 

 and third at base more or less rufous. Prothorax rather more than one-half 

 wider than long, slightly narrower at base than apex, finely rugulose at base; 

 apex nearly truncate ; median line distinct, abbreviated before and behind ; 

 transverse impressions distinct; basal impressions rather shallow : sides with the 

 margin very narrowly reflexed, moderately arcuate in front, slightly sinuate 

 behind ; hind angles subrectangular. Elytra about one-half wider than the 

 thorax, oblong-ovate, finely striate, more finely at sides and tip ; strife distinctly 

 punctate to behind the middle, the third with the dorsal punctures as in bifos- 

 sulatum, the first very slightly in front of the middle, the second about one-fourth 

 from apex. Beneath greenish black, shining. Legs feneo-piceous, tlie femora at 

 base and the tibise beneath rufous. Length .20-. 24 inch ; 5-6 mm. 



Smaller than bifossv latum, with the surface more shining and very 

 finely alutaceous. The thorax is slightly longer in proportion to its 

 width and less narrowed behind, with the sides less strongly arcuate, 

 the apex nearly truncate and the hind angles subrectangular The 

 elytra are usually moi-e finely striate, with the striae more finely 

 punctured. The antennae, palpi and femora are more rufous at base 

 and the tibiae are rufous beneath. 



