10. Least distance between middle coxae and coxal plates less than half 

 the length of the latter (measured along a continuation of the same 

 line.) 



Punctures along inner margin of hind tibia well separated; size 

 smaller (8 to 9 mm.) Greater portion of Northern U. S. and 



Canada.) seriatus 



Punctures along inner margin of hind tibia so close set as to form 

 a continuous groove; size larger (loto n mm.). (California) brevicollis 

 Least distance between middle coxae and coxal plates rather more 

 than half the length of the latter; elytra with small sub-lateral yel- 

 low spot behind the middle. (Rocky Mountains to Pacific Coast.) lugens 

 Form a little more obtuse, reticulation coarser var. perplexus 



1 1. Inner apical spur of hind tibia longer than the basal joint of the tarsus 12 



Inner apical spur of hind tibia never longer, usually distinctly shorter 

 than the basal joint of the tarsus 13 



12. Long spur of hind tibia stouter and more abruptly pointed at tip in 

 the male than in the female; intermediate legs of male unmodified; 



four anterior tarsi of male distinctly pubescent beneath punctatus 



Long spur of hind tibia similar in the sexes and very gradually point- 

 ed ; middle femora of male fimbriate with long hairs on the posterior 

 margin; middle tibiae (o*) with a fringe of shorter hairs on the inner 

 margin; four anterior tarsi (c?) very feebly thickened and with very 

 little glandular pubescence beneath aeruginosus 



13. Anterior protarsal claw of male rather broad and of equal width 

 throughout, the tip nearly squarely truncate; both claws shorter than 



usual triton 



Anterior protarsal claw of male conspicuously toothed beneath; very 

 small species, rarely (semipunctatus) attaining a length of 7 mm. ; 



elytra not vittate 14 



Anterior protarsal claw of male with a small tooth near the base; 



elytra yellow with black vittae 1 



Anterior protarsal claw of male not toothed beneath (except lutosus 



and griseipennis, in both of which the anterior tarsi are extremely 

 widely dilated), the tip normally acute 16 



14. Surface distinctly aeneous; the elytra usually paler, brownish to 

 brownish piceous. 



Apex of ungual tooth subapical in position; form of body more 



oval punctulatus 



Apex of ungual tooth median in position ; body narrower and 



more oblong oblongulus 



Surface not aeneous, color black. 



Abdomen without sexual modification, side margins of prothorax 



rather broad sharpi 



Abdomen of male with a system of parallel rugae on the third 

 segment, side margins of thorax appreciably narrower.... semipunctatus 



15. Prothorax yellow with basal and apical margins blade except at sides; 

 meshes of elytral reticulation almost completely impunctate, but with 



