COLKOPTERA. 59 



These Insects are connected on the one hand with the Helopii, and 

 on the other, with the (Edemerae, and still more closely with Nothus, 

 a subgenus of the same tribe : such are the principles which have 

 guided us in the division of this family. 



In some, the antennae 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 fii'st tribes. 



Those of the first or the Helopii, have their antennae covered at 

 base by the margin of the liead ; they are generally filiform or slightly 

 thickened towards the extremity, generally composed of almost 

 cylindrical joints attenuated at 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 maxillary 

 palpi is larger and securiform, or in the figure of a reversed triangle; 

 the eyes ai'c oblong, and reniform or emarginated. None of the legs 

 are fitted for leaping ; the penultimate 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 larvae 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 under the bark of trees. 



This tribe m-ostly corresponds to the genus 



Helops, Fab. 



In some, the body is alsoelliptical, strongly arcuated above, or 

 very convex; the antennae, at most, as long as the thorax, com- 

 pressed, and dilated like the teeth of a saw towards the extremity ; the 

 thorax is transversal, plane above, either trapezoidal and becoming 

 widened posteriorly, or almost square ; and the elytra frequently ter- 

 minate in a point or by a tooth. The posterior extremity of the 

 prsestevnum projects in a little point, which is received into a forked 

 emargination of the mesosternum. 



In these the mentum is broad, and conceals ths origin of the max- 

 illae. The middle of the posterior extremity of the thorax projects 

 along the side of the scutellum in the manner of an angle. Such is 

 the 



Epitragus, La/.* 



In the others the mentum does not cover the base of the maxillae, 

 and the posterior margin of the thorax is straight, or but slightly 

 dilated behind. 



* Lat., Gener. Crust, et Insect., II, p. 183, and I, x, 1. The maxillie are un- 

 gvuculated like those of Melasoma. This subgenus and the two following subgenera 

 are peculiar to South America. 



f2 



