196 MEMOIRS ON THE COLEOPTERA 



group is rather more widely diffused in geographic range than the 

 preceding, inhabiting the Rocky Mountains from Montana to 

 southern New Mexico and eastward well into Kansas and Texas. 



Side margins of the elytra very unstable in extent at least in the male, 

 acute but reflexed only at the humeral angles, becoming obtuse or 

 lost in some examples even before the middle, but in others extending 

 fully to apical sixth, in the female extending to about apical fourth; 

 body deep black and in great part shining above and beneath. Form 

 rather narrow and notably convex, broader and less convex in the 

 female; head opaque, strongly impressed transversely, coarsely and 

 closely punctate, the punctures very dense and asperate on the 

 vertex, each with a minute slender hair, the vertex impressed medially 

 as a rule; antennae stout, much compressed throughout; prothorax 

 almost as in opaca, nearly one-half wider than long, the apex deeply 

 sinuate, two-thirds to three-fourths as wide as the base, the latter 

 broadly bisinuate, posteriorly oblique laterally, equal in width to 

 the elytral base, the apical angles acute, slightly blunt at tip, the 

 basal strongly and obliquely acute; sides broadly arcuate, broadly 

 sinuate basally; surface alutaceous, coarsely, densely punctate, the 

 punctures granose at their anterior margins and very irregularly 

 condensed, leaving impunctate spots, the sides broadly, feebly con- 

 cave basally, more narrowly so anteriorly, the moderately reflexed 

 edges rather thick, densely punctate; elytra three-fifths (9) to 

 three-fourths (cf ) longer than wide, only just visibly wider than the 

 prothorax (cT) to one-third wider (9), convex, strongly shining, 

 deeply and very confusedly rugose, with large uneven indentations 

 and coarsely but not deeply punctate, each puncture with an anterior 

 asperity, the surface irregular, having generally about four narrow and 

 close-set longitudinal ridges, which are feeble, very irregular and more 

 visible inwardly; abdomen shining, with fine and feebly asperulate 

 punctulation, punctate posteriorly; legs slender. Length (cf, 9) 

 13.0-15.0 mm.; width 5.8-7.2 mm. New Mexico (Fort YVingate). 



nitidula n. sp. 



Side margins of the elytra feebly cariniform and rather constant, always 

 extending to about the summit of the apical slope. Form stouter 

 than in nitidula and larger in size, similarly deep black throughout 

 but more opaque, the elytra not so shining, similarly convex; head 

 nearly similar but rather less densely and strongly punctured, 

 the antennae distinctly longer; prothorax larger, the sides gradually 

 feebly converging from base to apex, similarly sigmoid, rounding 

 anteriorly, broadly sinuate basally, the basal angles obliquely 

 acute and prominent; surface but very feebly convex, opaque, 

 coarsely, very densely punctate, rather more broadly and less 

 strongly concavo-explanate at the sides, the punctures not evi- 

 dently granuliferous; elytra barely more than one-half longer than 

 wide, at base as wide as the total thoracic base to slightly wider, 

 just visibly widest behind the middle, the sides very feebly arcuate, 

 rounding behind to the large and conspicuous apical lobe, dis- 



