418 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io4 



Punctures of median longitudinal line of pronotum about the same size as 

 those of the transverse furrows, the third furrow usually continuous across 

 and extending backward at the middle, merging in a wide triangle with the 

 midline; elytral intervals smoothly convex, their inner edges irregular, not 

 so deeply, sharply, and distinctly crenate as in preceding species, the 

 crenations appearing more as small triangular notches; color ferrugineus; 

 smaller species, 2.8 to 3.4 mm.; Mexico .... canoensis, new species 



11. Light brown species with five transverse swellings on pronotum . ... 12 

 Usually darker colored species, with three or less transverse smooth areas on 



the ponotum 14 



12. Clypeal emargination more or less broadly, evenly rounded at middle; first 



or apical ridge of pronotum distinctly tuberculate even at middle, trans- 

 verse furrows weak and poorly developed, punctures indistinct; abdominal 

 segments 3, 4, and 5 apparently connate at middle, terminal segment not 

 distinctly crenate anteriorly; Texas, Arizona, Mexico . . blandus (Fall) 

 Clypeal emargination angular at middle; first or apical ridge of pronotum 

 indistinctly tuberculate at sides and almost smooth at middle, transverse 

 furrows strong with distinct punctures; abdominal segments not connate, 

 terminal segment distinctly, strongly crenate anteriorly at middle . . 13 



13. Posterior tibia less than three times as long as wide at apex, rather suddenly 



narrowed from basal quarter to knee, the inner edge curved or arcuate in 

 outline; elytra short and convex, width 1.45 mm., length 1.85 mm.; 



Mexico veraecrucis Bates 



Posterior tibia more than three times as long as wide at apex, the inner edge 

 nearly straight, width gradually reduced to knee; elytra longer, width 

 1.55 mm., length 2.0 mm.; Arizona to Texas, Mexico. 



quinqueplicatus Horn 



14. Posterior tibia without oblique ridge 15 



Posterior tibia with oblique ridge; Pacific Coast of United States ... 22 



15. Species less than 3 mm. in length, width less than half the length; Brazil and 



Bolivia 16 



Species more than 3 mm. in length, or width more than half the length. . 18 



16. Midline of metasternum vaguely evident but not deeply impressed, anterior 



postcoxal line absent at middle, vague near sides, angular depression in 

 front of posterior coxal plates small and weak; pronotal punctures mostly 

 close in deep furrows; Bolivia, Paraguay, Argentina. 



bolivianus, new species 

 Midline and postcoxal line of metasternum deep and distinct 17 



17. AVidth of posterior femur barely one-lialf tlie length ; apical width of posterior 



tibia one-third the length of the tibia; Brazil . . . manaosi, new species 



Width of posterior femur more than half the length; apical width of posterior 



tibia one-half the length of the tibia; Brazil . . santaremi, new species 



18. Elytra fimbriate with moderately long fine hairs 19 



Elytra not fimbriate 20 



19. Tenth elytral interval very flat to concave, others convex; Chile. 



indefensus (Schmidt) 

 Tenth elytral interval convex, not differing from others; strongly convex, 

 oval; only the anterior transverse groove of pronotum present; Argen- 

 tina inflatus, new species 



20. Rufopiceous; midline of metasternum deeply impressed at middle; clypeus 



weakly dentate; Argentina placidus (Schmidt) 



Lighter colored; midUne of metasternum fine, not or only very weakly im- 

 pressed; United Sv^ates 21 



