longer than the ultimate, which is fusiform, and broader than the former, the first quarter tawny, the remainder dark brown caused by a dense pubescence amongst which are one or two delicate hairs. Occiput depressed, shiny black, with no reflections.

Thorax and scutellum brilliant bluish-green, the 4 scutellar spines short and tawny, those of the ♂ longer than in the ♀; dorsum thinly dusted with tawny, humeri slightly tawny. Halteres greyish-white, but darker at the head.

Legs very minutely clothed with stiff hairs, on the whole dark tawny, anterior tarsi fuscous; apex of middle protarsi and remaining 4 joints fuscous; posterior tarsi greyish in certain lights Protarsi longer than sum of remaining joints, more so the anterior; posterior epitarsi slightly longer than those of the other legs; posterior femora thickened.

Wings (fig. 7), except for the tawny subcostal and marginal cells, unclouded, being either clear or slightly coloured; costal cell normal, not widened; anal angle but distinctly curved; anterior cross-vein and 3rd longitudinal not having a common origin from the 2nd vein, the cross-vein leaving the 3rd vein about half its length from the 2nd vein so that the 1st submarginal cell is more or less proximally truncated or obtuse; cross-vein not short, anteriorly oblique Third vein not angulated but gently curved, the anterior branch arising at a slightly acute angle and bismuated to the costa, the 1st smuation the stronger; this branch is about twice the length of anterior cross-vein. Vein between the discal and 5th posterior cells not quite as long as the anterior cross-vein. Of the 4 veins from the discal cell the 3rd may be absent, rudimentary, or short (absent in the figure). The distance from the posterior margin of the confluence of the 5th and 6th longitudinals equal to the length of the anterior cross-vein.

Abdomen with 7 segments, of uniform width in the ♂ and not as broad as the thorax; in the ♀ broader than the thorax and but little narrower at the base. First segment of a deep shiny purple, the remainder clothed with a dense silky and silvery pubescence which in certain lights shows a darker band on the posterior margin of each segment, due to a slight depression. There are longer silvery hairs at the sides. At times the silvery vestiture may be thinner, showing the ground-colour of the segments (except the 1st) to be tawny This last feature was noticed in a male.^* The 8th segment, when visible, is bare and of a deep purple, the genital organs tawny.

♂ J. Length, 9–5 mm; wing, 7–5 mm.

♀. Length, 10 mm.; wing, 8–25 mm

Habitat.—Wellington (Howes); Mount Arthur Tableland, taken in hot sunshine, January, 1889 (Hudson), Kaitoke, November, 1910 (Hudson); Arthur's Pass, 3,000 ft, December, 1914 (Hudson).

This species, on account of abdomen, is unique Although I have not yet met with specimens, it is apparently a common species.