Memoirs on the coleoptera

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 concave
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 evidently
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-