Memoirs on the coleoptera

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MEMOIRS ON THE COLEOPTERA
mesosternum. This character is certainly an important one among
the American members of the Asidini, though apparently
of less
definite value among the European representatives of the tribe,
the importance of a character being determinable solely by its
constancy and consistency. With a general
habitus which is suf-
ficiently uniform and readily recognizable, the body assumes two
distinct forms, the species of the first group being more ventricose
and larger than those of the second, glabrous in the former, sparsely
covered with rather long erect setae in the second; the elytra are
strongly margined at the sides nearly to the apical angles and quite
uniformly throughout the genus, but, singularly enough, the only
species to exhibit any sign of discal costae is the type named Pele-
cyphorus obsoletus, by LeConte, though just why it was placed in
that genus is not clearly understood, as the fourth male maxillary
palpal joint is sharply recti-triangular, while in the female it is
acute at the angle of attachment, just as in all the preceding genera
to Euschides in the table. The mentum is short and
subsequent
transversely obtrapezoidal, touching the sides of the buccal opening,
which are moderately short, obtuse in the first group and rather
acute at tip in the second. The base of the prothorax
or broadly sinuate, the basal angles generally acute and sometimes
is truncate
obliquely prominent, the elytral base about as wide as the thoracic
base and the humeral angles obtuse and usually rather blunt though
evident, the reflexed cariniform margin not notably more elevated
basally. The trochantin is well developed, the eyes, labrum and
epistoma as in Euschides, the anterior tibiae generally finely everted
and acutely aciculate externally at apex, the legs and tarsi moderate;
the antennae are rather slender, with the tenth joint somewhat
abruptly wider nearly as in Trichiasida. The two subgeneric
groups may be defined as follows:
Body larger and rather stout, more ventricose, glabrous, the tarsi rather
long, having short spinuliform hairs beneath Group I
Body smaller, sometimes very small, more parallel, the prothorax never
more than slightly narrower than the elytra; dorsal surface sparsely
clothed with erect flavo-fulvous setse; tarsi much shorter, densely
clothed beneath with inclined stiff pale hairs Group II
The first of these groups occurs in Arizona and southern California,
but the second seems to be confined to the latter region and is more
maritime, being particularly abundant near San Diego.