_Gen. Char._: BODY glabrous and much punctured. HEAD globose and curving to the thorax posteriorly; _ocelli_ in a triangle far forward on the vertex; _antennæ_ slightly subclavate, the scape not half so long as the flagellum, the first joint of which is robust, subclavate, and twice the length of the second, which, with the rest, are subequal, very slightly lengthening to the terminal one, which is as long as the basal one and laterally compressed; _face_ slightly convex, cheeks large and convex; _clypeus_ lunulate, convex, and with two minute central teeth on its front margin; _labrum_ longitudinally oblong, rather broadest at the base and slightly waved laterally, concavo-convex and subemarginate at the apex; _mandibles_ subequal, tridentate at the apex, and the central tooth obtuse; _cibarial apparatus_ moderately long, _tongue_ twice the length of the labium, with a small knob at its apex; _paraglossæ_ very short, almost obsolete, coadunate at the base; _labial palpi_ two-thirds the length of the tongue, the two first joints membranous and long, the first one-third the length of the second, which tapers to its acute extremity, before the end of which the two terminal, subclavate, very short, subequal joints are inserted; _labium_ half the length of the tongue, slightly produced in the centre of its inosculation; _maxillæ_ subhastate, two-thirds the length of the tongue; _maxillary palpi_ three-jointed, short, robust, equal, and collectively subfusiform, the terminal one rather acute. THORAX globose; _prothorax_ inconspicuous; _scutellum_ lunulate; _post-scutellum_ linear, transverse; _metathorax_ declining; _wings_ with two submarginal cells, and the commencement of a third indicated, the second larger than the first, subtriangular, and receiving both the recurrent nervures, one at each of its extremities; _legs_ short, rather robust, subsetose and spinulose; _posterior tibiæ_ convex externally and with their plantæ rugose, the latter covered beneath with a dense brush of short hair; _claws_ simple. ABDOMEN cylindrical, convex above, retuse at the base, and the first and second segments slightly constricted at their extremity, obtuse, and from the end of the third segment sensibly declining to the apex; plane on the venter, where, from the second segment, the plate of each, excepting the glabrous terminal one, is covered with a dense brush of short hair for the conveyance of pollen. The MALE differs in the _antennæ_ being rather longer, more distinctly filiform, the seventh segment of the _abdomen_ concealed under the extremity of the sixth, and the _venter_ from the third segment longitudinally deeply concave, the plate of the third itself covered with hair; the _claws_ more robust and each equally bifid, not bidentate. NATIVE SPECIES. 1. _truncorum_, Linnæus, ♂♀. 3-3½ lines. (Plate XIII. fig. 3 ♂♀.) _truncorum_, Kirby. GENERAL OBSERVATIONS.