190 MEMOIRS ON THE COLEOPTERA 



Silusa Erichs. 



The species hitherto assigned to Silusa in this country are rather 

 heterogeneous and may require some division into groups of at 

 least subgeneric value; decolorata and vesperis, for example, are 

 each quite dissimilar in facies from californica and valens, and in 

 different directions. 



Silusa rutilans n. sp. Parallel, convex, pale brownish-rufous through- 

 out, the fourth tergite black, the legs pale testaceous; lustre subalu- 

 taceous, the elytra and abdomen more shining; pubescence abundant, 

 pale and stiff; head rather large, closely, shallowly punctate, moderately 

 transverse, convex, fully three-fourths as wide as the prothorax, the 

 eyes rather small, not prominent, at almost their own length from the 

 base, the tempora very gradually arcuato-converging thence to the base; 

 antennae moderately long, gradually and rapidly becoming very stout 

 apically, pale, the first three joints slender, just visibly and regularly 

 decreasing in length, fourth nearly as long as wide, obtrapezoidal, the 

 tenth three-fourths wider than long, the last ogival, fully as long as the 

 two preceding; prothorax two-fifths wider than long, convex, widest 

 before the middle but with the sides broadly rounded, becoming per- 

 ceptibly converging and sinuate near the very distinct basal angles, 

 unimpressed, the ground sculpture coarse and irregular, the punctures 

 granuliform and moderately close; elytra parallel, slightly transverse, 

 coarsely, closely and strongly asperate, just visibly wider and a third 

 longer than the prothorax, the apices deeply sinuate laterally; abdomen 

 parallel, rather thick, distinctly narrower than the elytra, strongly and 

 rather closely asperate basally but becoming more sparsely so apically, 

 the three very deep subequal basal impressions simply and not densely 

 punctate; all the tergites subequal in length; basal joint of the hind tarsi 

 one-half longer than the second, the fifth as long as the first two, the 

 claws rather long and feebly arcuate. Length 2.2 mm.; width 0.57 mm. 

 Pennsylvania (suburbs of Philadelphia). 



Recognizable by the subparallel and rather convex form, gradu- 

 ally very stout and somewhat compact antennae, coloration and 

 sculpture. 



Silusa modica n. sp. Parallel, less convex and darker, slightly blackish, 

 the pronotum paler laterally, the abdomen red-brown, the fourth tergite 

 black, the legs pale; sculpture nearly similar, except that the pronotal 

 granules are feebler, less well defined or more confused with the irregular 

 ground sculpture, the pubescence nearly similar; head nearly similar but 

 with larger eyes, they being at but little more than half their length from 

 the base, the tempora feebly converging and arcuate to the base; an- 

 tennae similar but rather looser and not quite so thick distally, the last 

 joint longer than the two preceding; prothorax distinctly shorter and 

 more transverse, less convex, three-fifths wider than long, widest at 

 less than two-fifths from the apex, where the sides are broadly subangu- 



