Memoirs on the coleoptera

io MEMOIRS ON THE COLEOPTERA
hesperus Wickh., in this generic assignment. It is probable that
the feeble sulcation of the elytra referred to is to some extent ac-
cidental, as before remarked; and in fact one of my examples of
oblongns exhibits a faint longitudinal costulation by oblique illu-
mination, though this is unaccompanied by the feeblest trace of true
striation. But in hesperus mention is made of a distinct frontal
fovea, and it is said that the antennae are relatively much stouter
than in lecontei; as the antennas in the latter are not materially more
slender than in the prevailing type of Morychus, it may be that
we have here another decisive divergence; these discrepancies,
together with the aberrant coloration of the legs, render the as-
signment of hesperus to Morychus somewhat doubtful. Lateralis
Fall, is also doubtfully attached to Morychus and I would assign it
to the genus Tylicus, which follows, in company with subcanus Lee.,
if it were evident that the abdominal sutures were perfectly straight
and not arcuate. Subcupreus Fall, is almost undoubtedly
a close
congener of oblongus and subsetosus, but of ceneolus Lee., the pub-
lished characters are not sufficient to warrant a decision.
Tylicus n. gen.
The perfectly rectilinear abdominal sutures in this genus form a
striking and apparently valid taxonomic character, accompanied as it
is by a number of other more or less evident differences. Thevesti-
ture of the upper surface, for example, is not uniform in distribution
as it is in Morychus, but is condensed into streaks and spots; but,
singularly, this condensation is not accompanied by any material
condensation of the punctures, for under sufficient optical power
the punctures are observed to be distributed uniformly under these
patches of condensed pubescence, just as they are in Morychus,
showing that it is only those genera in the tribe Pedilophorini having
deep and abrupt fossae for the reception of the hind legs, that the
sculpture of the elytra becomes irregular.
The single type of Tylicus may be known by the following short
diagnosis of LeConte:
Elongate-oval, convex, rounded behind, obliquely narrowed in front of
the elytra, black, irregularly mottled with very short gray pubescence
like hoar-frost and thinly clothed with short, erect, black
bristles; under surface finely, densely punctured, finely pubescent;
legs piceous, the tarsi paler, the fourth [third] joint with a long lobe.