HlSTERID^E 223 



convex, without trace of indentation, the punctures very coarse, rather 

 deep and close-set, with an area at each side of the base impunctate; the 

 very convex pygidium is almost as coarsely and still more closely and 

 very deeply punctate, with a large, abruptly smooth area at apex, the 

 surfaces more polished than in the preceding species and the sculpture not 

 quite so dense; prosternal lobe finely but strongly beaded throughout, 

 the mesosternal sinus broad and very feeble though evident; three tibial 

 teeth rather large, high and very acute, the distal minutely bifid. Length 

 3.75-4.5 mm.; width 3.0 3.35 mm. Kansas (Sedgwick Co. and Mt. Hope). 



This species, while allied to the preceding, differs in the evident 

 minute punctulation of the anterior parts, slightly less densely 

 sculptured and more polished pygidia, with much larger terminal 

 smooth area and, very radically, in the sulcus of the inflexed ely- 

 tral flanks; the sulci in densicauda are wholly obsolete in basal 

 two-fifths or more. 



The following species is allied to the two preceding but is mate- 

 rially larger: 



*Hister sternalis n. sp. Oblong-oval, convex, black and very shining, 

 the legs barely less than black; head smooth, unimpressed, with the stria 

 strong and entire, transverse on the front; prothorax rather long, two- 

 thirds wider than the median length, smooth, with a single basal line of 

 fine feeble punctures; inner lateral stria not very far removed from the 

 edge, parallel, more or less sinuous medially and not quite attaining the 

 base, the outer fine, close to the edge and not extending posteriorly as far 

 as the middle, the intermediate surface not more convex; elytra much 

 abbreviated, two-fifths longer than the prothorax, with broadly arcuate 

 sides; four discal striae entire, smooth, gradually less coarse inwardly, 

 the fifth represented by a very short fine line at apex, the sutural a fine 

 line from just before the middle and not attaining the apex; humeral and 

 subhumeral striae wholly wanting, the oblique humeral very fine; pro- 

 pygidium very coarsely, closely punctate, more finely near the base, in 

 the male slightly impressed laterally and with a smooth basal space at 

 each side, these characters obsolete in the female; pygidium with very 

 coarse and close-set punctures, abruptly smooth at apex in both sexes; 

 two striae of the prosternum distinct, diverging basally; mesosternal bead 

 entire, the sinus broad, gradual and rather shallow, very distinct; an- 

 terior tibiae with four external teeth, the basal a minute denticle, the 

 apical short and broad, obtusely bifid. Length 3.8-4.8 mm.; width 3.0- 

 3.35 mm. Mexico (Durango City, Durango), Wickham. 



Differs from densicauda in its still much coarser punctures of the 

 pygidia, less coarsely impressed elytral striae, the fifth and sutural 

 much less developed, and in the very short outer thoracic stria. 

 From cribricauda it differs in the still coarser punctures of the 

 pygidia and short outer thoracic stria; the elytral striae are nearly 



