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Show 468 INSECTA. the principles which have guided us in the division of this family. In some, the antennre are approximated to the eyes, and the head is not prolonged in the manner of a proboscis, but terminated at most by a very short snout. They will form our four first tribes. Those of the first or the HELOPII, have their antednm covered at base by the margin of the head; they are gene. rally filiform or slightly thickened towards the extremity generally composed of almost cylindrical joints attenuated a~ base, of which the penultimate ones are frequently a little shorter, and in the form of a reversed cone, and the last is usually almost ovoid; the third is always elongated. The extremity of the mandibles is bifid; the last joint of the max· illary palpi is larger and securiform, or in the figure of a re· versed triangle; the eyes are oblong, and reniform or emar. ginated. None of the legs are fitted for leaping; the penul. timate joint of the tarsi, or at least of the last ones, is almost always entire or not deeply emarginate; their terminal hooks are simple, or without fissure or dentation; the body is most commonly arcuated above, and always solid and firm. Such of the larvre as are known to us are smooth, filiform and glossy, with very short legs, like that of a Tenebrio. They are found in old wood, and the perfect Insect lives un. der the bark of trees. This tribe mostly corresponds to the genus HELOPs, Fab. In some, the body is almost elliptical, strongly arcuated above, or very convex; the antennre, at most, as long as the thorax, compress· ed, and dilated like the teeth of a saw towards the. extremity; the thorax is transversal, plane above, eithet· trapezoidal and becom· ing widened posteriorly, or almost square; and the elytra frequently terminate in a point or by a tooth. The posterior extremity of the prresternum projects in a little point, which is received into a fork· ed emargination of the mesosternum. In these the mentum is broad, and conceals the origin of the mat· illre. The middle of the posterior extremity of the thorax projects COLEOPTERA. 469 elong the side of the scutellum in the manner of an angle. Such is the . EPITRAGus, Lat.( 1) In the others the mentum does not cover the base of the maxillre, and the posterior margin of the thorax is straight, or but slightly dilated behind. CNODALoN, Lat. Where, from the fifth joint, the antennre are strongly compressed and serrated, and where the head is much narrowet· than the thorax( 2). CAMPSIA, Lepel. and Serv.-Camaria, Id. Where the antennre, from the sixth joint, are slightly serrated, and the bead is as wide as the posterior margin of the thorax. T~e body is proportionally longer and less convex, and the thorax· wi,der posteriorly(3). In all the other Helopii, the mesosternum presents no remarkable emargination, and the posterior extremity of the prresternum is not extended into a point. Here the body is sometimes ovoid or oval, and at others more oblong but narrowed at both ends; it is never cylindrical or linear, nor much flattened. Certain subgenera have been formed with Ilelopii, which approach the first in their strongly inflated body, which is gibbous posteriorly. Those, in which the body is almost ovoid or short, and the thorax transversal, plane or simply curved, compose the following 'subgenera. SPHENISous J Kirby. Easily mistaken at the first glance for Erotylus, and in which, as (1) Lat., Gener. Crust. et Insect., II, p. 183, and J, x, 1. The mnxillre are un. guiculated like those of Melasoma. This subgenus, and the two following subge· nera are peculiar to South America. (2) Lat., Gener. Crust. et Insect., II, p. 182, and I, x, 7. (3) Encyc. Method., article Spltenisque. Messrs Lepeletier and Serville give but ten joints to the antennre of the Camarire, a character which would distinguish them from the other Helopii: but we have distinctly seen eleven in various Helopii from Brazil, which appear to us closely allied to the C. nit ida, quoted by them. Until we can verify this anomaly in the individuals examined by those ·.gcntlcmcn, we think it best to unite the two subgenera. Besides the Cnodalon trroratum of Germar,quoted in this article, refer the 'lbxicum geniculatum and nigripea, ejusd., to the same subgenus. |
