378 Memoirs on the Coleoptera 



preceding, in peculiarities of abdominal vestiture; the humeral 

 protuberance is more prominent than usual though rounded. The 

 propleura are denuded in two separated spots. 



*Trichobaris rugulicoUis n. sp. — Stout, subparallel and only feebly 

 convex, black and feebly shining where denuded; vestiture of lineiform 

 whitish scales coarser than in mucorea but not denser, more condensed 

 at the thoracic apex, with the denuded spots as in trinotata, the under 

 surface with large and oval dense scales, denuded in two separated pro- 

 pleural spots, the polished abdominal spot confined to the third and 

 fourth segments; beak (9) short, arcuate, stout and cylindric, barely 

 as long as the prothorax, partially squamulose and closely punctate, the 

 upper surface not abruptly declivous at base; prothorax a fourth wider 

 than long, the sides distinctly converging, moderately and evenly arcuate, 

 more rounding for a short distance anteriorly to the constriction; punc- 

 tures strong, in great part forming longitudinal rugulosity, the smooth 

 median line cariniform; elytra broad, parallel, rapidly very obtuse at 

 apex, three-sevenths longer than wide, two-fifths wider than the pro- 

 thorax and two and one-half times as long, the humeral angles obtusely 

 subprominent; striae moderate, punctate, the broad and nearly flat 

 intervals with the usual rugose sculpture; squamules oblique at the sides 

 of the intervals as in mucorea and others of this section. Length ( 9 ) 

 5.8 mm.; width 2.6 mm. Mexico (Durango City, Durango), — Wick- 

 ham. 



Differs from mucorea in its relatively much shorter and broader 

 elytra, shorter and stouter beak and broader lineiform squamules 

 of the entire upper surface. 



It is interesting, on forming series of the males and females of 

 trinotata, to observe the sexual differences, which are peculiarly 

 marked in that species, occurring rather abundantly over the eastern 

 parts from Kansas to New England and southward to Key West, 

 Florida. The male is notably shorter and broader than the female, 

 the outline in the latter sex being peculiarly elongate-oval and 

 narrow; at first sight these series might be thought to represent 

 different species. The terminal abdominal ligula of the male is 

 extremely small and feeble and is obtusely angulate. The following 

 species is evidently allied to trinotata but is much smaller and more 

 slender: 



Trichobaris impotens n. sp. — Slender, cylindric, moderately convex, 

 deep black, barely at all shining; the vestiture of the upper surface is 

 loose, not concealing the integumants and consists of small lineiform 

 scales, even smaller and finer than in trinotata; on the under surface 

 they are but little broader, isolated, but denser and a little broader at 

 the extreme sides, the propleura denuded in two spots; beak arcuate, a 



