14 MEMOIRS ON THE COLEOPTERA 



exactly as in the ustidatum group, while in bifossulatum it is punc- 

 tulate, feebly impressed, distant from the margin and subsimilar to 

 the seventh stria; it also differs in the position of the dorsal punc- 

 tures, the anterior being at about the middle, while in bipunctatum 

 it is at basal third or fourth. The mentum tooth in bifossulatum 

 is elongate, tapering and truncate at apex; it sometimes becomes 

 shorter and more broadly truncate however, as in cheyennense and 

 nuperum. We have seven rather distinctly characterized species 

 as follows: 



Mentum tooth tapering, truncate or broadly rounded at tip, where the 

 tooth is always very much narrower than the width of the mental 

 recess at each side of it, the sides of the mental sinus more diverg- 

 ing 2 



Mentum tooth rather broad, more convex, subparallel, the very wide 

 truncate apex not narrower than the mental recess at each side, 

 the sides of the mental sinus' subparallel and arcuate 4 



2 Larger species; western regions of the continent beyond the Rocky 

 Mountains. Oblong, moderately convex, alutaceous, black, bright 

 bronze above, dark metallic green beneath; legs and antennae black 

 throughout, the latter long and slender; head four- fifths as wide as 

 the prothorax, with very prominent eyes; prothorax fully one-half 

 wider than long, evidently narrower at base than apex, the sides 

 inflated, rounded, oblique and broadly, feebly sinuate basally to the 

 basal angles, which are broadly obtuse but with sharp prominent 

 apex; stria moderate, the basal impression broad, distinct, the fovese 

 large, shallow and rugose; carinae obsolete; elytra oblong, parallel, 

 rapidly rounding at base, obtuse at apex, fully one^half longer than 

 wide, not quite one-half wider than the prothorax, the striae rather 

 fine; punctures small, a little larger laterally, those of the eighth stria 

 fine but evident; surface more densely alutaceous toward the sides. 

 Length (cf 9 ) 5-7~7-O mm.; width 2.0-2.75 mm. Pacific coast 

 from Los Angeles to Kamloops, British Columbia and eastward to 

 Marysvale, Utah. Rather abundant bifossulatum Lee. 



Smaller species, inhabiting the eastern parts of the continent 3 



3- Body oblong, moderately convex, shining, especially in the male as 

 usual in this group, black, bronzed above, obscure metallic-green- 

 ish beneath; legs obscure rufous, the femora in great part blackish, 

 with metallic lustre; antennae black, obscure rufous at base, long 

 and slender, the outer joints much more than twice as long as wide; 

 head fully three-fourths as wide as the prothorax, the eyes very 

 large and prominent; prothorax fully three-fifths wider than long, 

 evidently narrower at base than apex, widest at the middle, the 

 sides evenly rounded, oblique basally, becoming parallel for a very 

 short distance before the angles, which are right; surface nearly as 

 in the preceding, the impressions large, shallow and rugose, the 

 carina obsolete; elytra oblong, parallel, two-fifths or more wider 

 than the prothorax, broader in the female; striae moderate, not 



