Memoirs on the coleoptera

82 MEMOIRS ON THE COLEOPTERA
The body in A stratus is moderate or rather small in size, roughly
and unevenly sculptured and apparently glabrous under low powers
of enlargement. The antennae are shorter and more moniliform
than usual, with the third joint shorter than in any other of our
genera, being about twice as long as the second but not longer than
the first, the tenth joint spongiose only on the parts left exposed
by the small subimbedded eleventh joint. The labrum is mod-
erately transverse and sensibly sinuate. The mentum differs from
that of any other American genus, except possibly
Stenosides and
Sicharbas, in completely and closely filling the entire buccal opening,
being contiguous
also to the closed mandibles and is without trace
of gular pedestal, nearly as in the European Asida; the palpi are
moderate or rather small, with the last joint never scalene. The
tarsi are short but slender and there is no exposed trochantin. The
anterior parts are not so small in relation to the hind body
as in
Pactostoma ( = 0loglyptus Lac.), the elytra unevenly convex, deeply
embracing the body beneath and with the humeral angle distinct
though varying in form specifically.
The three species may be known as follows:
Antennae broadened apically through the ninth and tenth joints. Body
rather narrow, only moderately convex; head transversely impressed
between the antennal prominences, also with a small median impression
on the occiput, the epistoma sinuato-truncate; antennae
a little longer than the width of the head; prothorax about a fourth
wider than long, the sides strongly prominent and narrowly rounded
at the middle, thence converging and feebly sinuate anteriorly and
equally converging and deeply sinuate basally, the base evenly
sinuato-truncate throughout, the angles right, slightly blunt, the
apex deeply sinuate with the angles bluntly rounded surface ;
densely,
subgranularly sculptured, broadly, feebly concave laterally, tumid
medially, with the median line impressed anteriorly, exterior to
which there are two small impressions on each slope of the tumidity,
also a larger rounded impression before the scutellum, the latter
small; elytra three-fifths longer than wide, gradually widening to
apical third, the side margins with tubercles and crests, one of which
forms the humerus, which is exposed beyond the thoracic base;
surface granulate, the suture flat, feebly elevated, each elytron with
an uneven medial ridge, connected by anastomosing ridges with
the suture and curving at apical fourth to meet a sutural ramus in a
stronger elevation, the ridge continued thence to the apex and having
an acute tubercle midway; legs rather short, the very short pale
stout hairs abundant and conspicuous; anterior tibiae with an everted
and very acute spiniforrn external angle at apex. Length 11.8-
13.7 mm.; width 5.5-6.5 mm. Texas contortus Lee.