AMERICAN COLEOPTERA. 13 



Mentum horizontal, nearly flat posteriorly, becoming rather 

 strongly concave in front, without trace of transverse ridge, 

 the setas at most short and inconspicuous, often wanting, 

 thoracic angles usually impressed 11. 



Mentum feebly oblique behind, strongly declivous in front, the 

 declivity more or less concave from side to side, its margin 

 posteriorly arcuate and convex, but without raised line 

 (except feebly in sierra); thoracic angles not impressed.. 12. 



Mentum horizontal or subhorizontal and nearly flat posteriorly, 

 more or less declivous in front, the declivity margined by 

 a more or less acute arcuate raised line and a row of erect 

 setas, the raised line sometimes rather ill defined or even 

 obsolete (more especially so in ingenua, lengii, basalts, 



pumila, angularis, misella, and tenuis) 13. 



9. Ungual tooth subapical, claws larger in the male, elytral costae 

 with more or less confused punctuation.... 16. schaefferi. 



Ungual tooth median or moderately post-median, claws not dif- 

 ferent in the sexes; elytral costas each with a single row of 

 punctures 10. 



10. Clypeus with sub-basal ridge or convexity extending from side to 



side, making the clypeal suture seem strongly impressed; 

 mentum convex along the basal and lateral margins, not 

 declivous in front, the transverse ridge absent and the 

 accompanying setigerous punctures nearly or quite want- 

 ing; terminal joint of maxillary palpi fully, or more than 



three times as long as wide 17. mentalis. 



Clypeus nearly flat, the basal ridge at most but feebly defined; 

 mentum with transverse row of setigerous punctures (the 

 setas often in part wanting), in front of which the surface 

 is feebly declivous. 

 Form less robust, prothorax widest near the middle, tooth of 

 claw only slightly post-median. 

 Mentum broadly subconvex, scarcely declivous in front; front 

 more finely and sparsely punctate than the clypeus. 



IS. conformis. 



Mentum more obviously declivous anteriorly; front and clypeus 



similarly punctate; clypeal margin more broadly reflexed. 



19. residua. 

 Form more robust, prothorax not or very slightly narrowed be- 

 hind; tooth of claw more strongly post-median; terminal 

 joint of maxillary palpus barely twice as long as wide. 



20. teiiebrosa. 



11. Punctuation of upper surface rather dense 21. COStulata. 



Punctuation rather fine and much sparser. 



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



