well known character to a position of primary importance in grouping the genera and subgenera; this relates to the degree of inflexion of the hypomera or inflexed sides of the pronotum, which divides the group into three very well defined sections thus:
| 1— | Hypomera moderately inflexed, nearly flat and wholly or in great part visible from the sides,—including such genera as Metaxya, Hydrosmecta, Atheta and many others. |
| 2— | Hypomera horizontal, though because of considerable warping of the surface, visible in very limited part from the sides,—including Dimetrota, Datomicra and others. |
| 3— | Hypomera strongly inflexed, in such manner as to be wholly invisible when viewed from the sides and including Acrotona, Colpodota, Coprothassa and others, as well as some related but distinct groups, such as the Hoplandriæ. |
The body in the first of these sections is more or less parallel and or larger size as a rule, in the second rather small to minute and generally with more tapering abdomen; in the third the body becomes on the whole still more limuliform, or with strongly tapering abdomen. The second character in point of importance relates to the formation of the sterna between the middle coxæ, and then follow several characters more particularly important in certain subsidiary sections, such as tarsal structure, impression of the abdominal tergites and form of the head, antennæ and lateral carinæ. Under the second of the above groups the have genera with the head parallel and others with the head basally inflated, and, among the latter, some with finely and others with coarsely faceted eyes. So it becomes sufficiently evident that we have among the Athetæ an unusual diversification of structural features.
The group Athetæ, as here construed, comprises the single genus Atheta of Fauvel, Bernhauer and some other recent authors.
Atheta Thoms.
Stethusa n. subgen.
If Dr. Bernhauer had examined the under surface of his Atheta klimschi, which he assigns to typical Atheta, he would probably have observed that in the sternal structure it bears very little resemblance to the true Atheta, where the mesosternal projection between the coxæ is more or less prolonged and slender to aciculate. In this subgeneric group the sterna between the coxæ are notably
