B. violacea Hutton.

B. violacea Hutton, Trans. N.Z. Inst., vol. 33, p. 6 (1901).

♀. Eyes broadly dichoptic with minute and scattered hairs; front broad, shiny blackish-brown with short scattered greyish hairs, and, above the antennae, a patch of greyish pubescence dead-black in certain lights and notched on the posterior margin. Antennae below middle line of head, long but not as long as width of head; 1st joint shiny black, the 2nd light brown, and both bristly (fig. 14); flagellum linear, covered by a dense stiff and black pubescence giving a tawny reflection in certain lights, composed of 7 almost equal segments except the ultimate which is about twice the length of the penultimate, both of which having terminal hairs. Face broad, shiny black with a few scattered silvery hairs; proboscis tawny and thinly hairy, palpi (fig. 15) 2-jointed, both of about equal length and projecting beyond the proboscis; 1st joint blackish and hairy, the 2nd brown with a darker apex, fusiform, minutely pubescent, and terminating in 3 bristle-like hairs. Occiput shiny black and depressed, hairy below.

Dorsum of thorax dull-bronzy with dull - greenish reflections and a finely punctured appearance; pleurae shiny blue-black and slightly hairy. Scutellum coloured as dorsum, with 4 light-brown but not large spines.

Wings clouded with greyish-brown but clear toward the apex; veins brown; stigma dark brown; base of the wing and anterior part of the costal cell clearer. First section of 2nd longitudinal vein about twice as long as anterior cross-vein, the 2nd section but slightly bent into the 1st submarginal cell; 1st section of 3rd vein a little longer than anterior cross-vein, which is perpendicular; 3rd vein curved upward to the bifurcation and thence sinuated downwards to the costa, the anterior branch arising almost at right angles and but very slightly bent to the costa (fig. 16); basal cells closed behind by an oblique transverse vein, the vein separating those cells represented by a furrow and clear line along which the membrane easily splits; confluence of the 5th and 6th longitudinal veins distant from the margin about three times the length of anterior cross-vein. Halteres with greyish-white heads and darker stalks.

Legs banded with dark and light brown, the proximal portions of each joint being of the latter colour, less distinct on the middle and anterior legs and more especially the latter, the tibiae of which have also a light-brown marking in the middle; posterior tibiae dark brown. The protarsi barely one-half as long as the whole joint, mostly light brown but for the apex, the remaining tarsal segments dark brown except for a light-brown band (sometimes indistinct) at the origin of each, but the anterior and middle tarsi vary from light to dark according to the light.