270 MEMOIRS ON THE COLEOPTERA 



and only about two-thirds as long as in that species; prothorax similar, 

 except that the sides from behind the middle to near the apical margin 

 are much more parallel, the punctureless sublateral spots near the base 

 smaller and the smooth tumid median line toward base only partially evi- 

 dent; scutellum parallel, obtuse at apex, very densely punctate and pubes- 

 cent; elytra distinctly wider than the prothorax, parallel, feebly narrowing 

 near the obtuse apex, very flat, blackish, finely and very densely punctate 

 almost throughout, the two median lateral pale lines distinct but the 

 more basal line of brevilineum very faint; prosternum (d 71 ) finely, trans- 

 versely punctato-rugulose; thighs strongly dilated and much com- 

 pressed. Length (cf ) 10.5 mm.; width 3.0 mm. Wisconsin (Bayfield), 

 Wickham. 



To be known at once from the same sex of brevilineum by the 

 very much more compressed femoral enlargement, less slender 

 antennae, absence of sutural pale marking on the elytra, confused 

 and not linear arrangement of the punctures just within the 

 exterior pale marginal crest of the elytra and, finally and very 

 obviously, by the sexual characters affecting the prosternum of the 

 male, the portion before the coxae in brevilineum being coarsely 

 and sparsely punctate in that species and not finely, transversely 

 punctate-rugose. In brevilineum the elytra have more or less of a 

 violaceous reflection, especially toward tip, but this is wholly 

 wanting in compressipes. 



Physocnemum densum n. sp. Larger than brevilineum and somewhat 

 stouter, similar in coloration and ornamentation but differing in sculp- 

 ture; head nearly similar, the antenna? (9 ) a little longer, the tenth joint 

 more than three times as long as wide; prothorax of like shape but some- 

 what larger, without velvety lustre, the sublateral smooth spaces near 

 the base less linearly oblique and more diffused, the tubercles larger and less 

 acute, the punctures small but deep, closely crowded, except in the smooth 

 spaces, but distinct, each with a short coarse dark hair; elytra similar in 

 general but with the punctures apically not becoming so sparse and each 

 with a much shorter and less erect hair, the apices more broadly rounded; 

 abdomen much less closely punctulate; last dorsal segment less punctate 

 and subglabrous, the legs similar. Length (9 ) 17.0 mm.; width 5.0 mm. 

 Kansas. 



The most important distinctive character, when comparison is 

 made with the female of brevilineum, is the sculpture of the pro- 

 notum; in that species the punctures become exceedingly crowded 

 and the deep black pubescence, especially medially and anteriorly, 

 becomes so dense as to wholly conceal the sculpture and produce a 

 homogeneous velvety-black surface. The examples of brevilineum 

 in my collections agree completely with the descriptions of Say 

 and LeConte and are from Dakota and Nebraska. 



