230 H. C. FALL. 



Anterior sulcus either lacking or fine and faintly impressed along the ex- 

 treme margin of the distal dilation ; posterior sulcus marginal, abbre- 

 viated apically; form rather strongly gibbous in profile; coarser punc- 

 tures relatively sparse and fine on the elytra and still less evident on 

 the pronotum 14. abbreviatum. 



Posterior sulcus lacking, anterior groove fine and close to the margin. 



15. gibbuliim. 



6. Metasternum carinate 16. cariiiatum. 



Metasternum not carinate 17. ventrale. 



7. Middle tibia? with an evident marginal groove 8. 



Middle tibiae without marginal groove 23. 



8. Metasternum carinate, form strongly elongate 18. puiictatuiii. 



Metasternum not carinate 9. 



9. Punctuation of elytra obviously dual, the surface finely punctulate with 



coarser punctures intermixed 10. 



Punctuation of upper surface fine and close throughout, the coarser punctures 



scarcely evident at any part except toward the elytral apex in densum. 



Size larger, form more robust and less obtusely rounded at the extremities, 



surface dull, coarser punctures distinct on the apical third or fourth 



of the elytra, color uniformly dark brown. . . 19. densiiiu. 



Size generally smaller, form more elongate, more obtusely rounded at ex- 

 tremities, surface shining, coarser punctuation practically absent 

 throughout; elytra piceous, head,prothorax and under surface rufous. 



20. dichronm. 



Punctuation distinctly coarser than in densum and dichroum, the punctures of 

 the disk nearly uniform in size, but obviously larger- at the sides of 

 the pronotum and near the elytral apex ; color and form as in 

 dichroum, surface distinctly less shining 21. nigripenne. 



Punctuation of pronotum fine and moderately close, a little coarser at sides; 

 that of elytra sparse and coarse, not intermixed with finer punctures; 

 black, head and prothorax slightly rufescent; size very small (1.5 

 mm.) 22. dispar. 



10. Color black or nearly so, punctuation relatively sparse, surface shining. 



23. nigril ilium. 



Color rufous to piceous, usually some shade of brown, punctuation closer, 



surface less shining 11. 



11. Pubescence longer and denser, obscuring or quite concealing the surface 



sculpture 12. 



Pubescence finer and sparser, rarely (robustnm) materially obscuring the sur- 

 face sculpture 13. 



12. Size larger (3 mm.), form more oblong, nearly twice as long as wide, scarcely 



gibbous in profile 24. vcsl i t u hi . 



Size smaller (2 mm.), more rotundate. but little more than one-half longer 

 than wide, distinctly gibbous in profile 25. pallia! urn. 



13. Coarser punctures of metasternum more evenly distributed, always present 



at sides 14. 



Coarser punctures of metasternum nearly confined to the central portion, 

 scarcelv evident at sides. 



