\ Natural History Bulletin. 



61 Head very flat, vertex slightly carinate, frontal margin triangular, 

 declining to the clypeus and but slightly separated from it by a linear 

 sulcus. 



Prothorax with conspicuous discal crests and deep grooves, giving 

 the disk the appearance of having five lines; occipital foveae 

 pubescent. Length 2.2 mm. Pennsylvania, Iowa. 



lineaticolh's. 

 Prothorax without discal crests and median sulcus; vertex 

 smoother in the middle. Virginia, Pennsylvania, bistriatus. 

 52 Vertex smooth, not carinate, front, behind the very retuse (J) margin, 

 deeplj^ excavated; $ front declivous, not retuse; occipital fovete pubes- 

 cent, antennee alike in the sexes. 



Vertex, sulcus deep; prothorax without crests or spines; shoulders 

 high, prominent, rounded. Totally impunctate, elytral basal 

 fove?e two, the intermediate wanting. Length 2.2 mm. Illi- 

 nois. frontalis. 



Vertex finely scabrous outside of the shallow circumambient sul- 

 cus; prothorax with four basa! spines. Length 1.9 mm. 



Michigan, Iowa. simplex. 



5' Vertex high, roof -shaped, smooth, carinate throughout, fovese nude, 

 border broad, flat, very densely punctured; tenth antennal joint {$) 

 globose, larger than the last, shoulders spinous. Length 1.7 mm. 

 Pennsylvania, Illinois, Iowa. ..-..- globosus. 

 4I Frontal margin not produced beyond the inter-antennal line, perpendicu- 

 larly declivous above the sub-frontal excavation; tenth antennal joint 

 {f,) very large. 

 7* Occipital fovepe nude, shoulders blunt, rounded, head orthognathous. 



Reddish-brown, median prothoracic sulcus nearly entire; f, tenth 

 antennal joint large, globose, with a small perforate fovea at 

 the base. Length 2.1 mm. Virginia. - - virginicB. 

 Black, antennje and legs red. median sulcus entire, obsolete. ,5 

 tenth antennal joint large, globose, foveate beneath. Length 

 1.6 mm. Virginia. {B. luciilejitus, Casey.) - sprettis. 



Var. a.; median sulcus of the pronotum indicated; fovea of the 

 tenth antennal joint very large - - - foveicornis. 

 Var. b. ; median sulcus short, more distinctly visible; tenth anten- 

 nal joint very little larger than the ninth ; last joint larger 

 than usual. ....--- punctifrons. 



71 Occipital fovese pubescent, shoulders spinous. . 



Reddish-brown or black, with red elytra, antennhe and legs; vertex 

 feebly carinate behind; ^ antennse with the basal joint bluntly 

 toothed below, the tenth large, globose, with a small perforate 

 puncture at the base below. Length 2.1 mm. Virginia, 

 Iowa. ........ denticornis. 



