a marginal fringe of scattered black hairs; spiracles silvery; halteres orange-yellow or orange-red. Wings clear, stigma brownish, veins blackish-brown; R_{4 + 5} running straight between cells R₃ and R₅: cross-vein r-m a little shorter than its distance from base of cell 1st M₂. Legs hairy, the femora somewhat thickened, the posterior particularly so; femora blue-black with greyish hairs, the posterior pair with numerous short bristles on lower side near apex; knees brownish-yellow; tibiae brownish-yellow darkening apically, the posterior pair darker and broader distally, all clothed with stiff greyish hairs longer on the posterior pair, which have a stiff golden pile below toward the apex; tarsi biownish becoming black apically, and clothed with stiff silvery hairs; posterior protarsi rather swollen and with a short golden brush beneath.

Abdomen shiny blue-black, immaculate, ovate, being broader than the thorax, and usually carried with the apical half turned downwards; clothed with short and scattered greyish hairs, but 1st segment with longer ones on each side.

♂. Eyes densely hairy, and holoptic over the greater part of the front; thorax and scutellum more densely and longer haired than the female; posterior tibiae silvery below toward apex, in some lights; posterior femora clothed with long erect bristle-like black hairs distally; abdomen black, slightly brown in recently emerged specimens, more hairy than female, the hairs black. Genitalia black; the genital segments, except the 9th, clothed with delicate hair-like bristles; claspers long and bifid (fig. 8).

This species, when on the wing, closely resembles the native bee (Halictus huttoni Cam.).

Larva.—The larva is of the rat-tailed type, but the siphon is short (Plate XLVII, fig. 3); the body, which is creamy-white, may attain a length of 20 mm. including the siphon; the transparent integument is transversely corrugated, and clothed with short bristles very minute on ventral surface, which otherwise is clothed with delicate hairs; along each side the integument is further broken up by longitudinal folds upon which the bristles are longer and more hair-like; from the lateral margin of each segment arises a tuft of 2 or 3 divergent bristle-like hairs which are distinctly longer than the surrounding vestiture and most conspicuous on the terminal segments, though absent on the ultimate segment, which is frequently withdrawn. The “prolegs,” which are armed with strongly recurved spines, vary in shape according to the contraction or expansion of the segments, being prominent knob-like swellings or merely transverse ridges of the integument. A characteristic feature is the form of the anterior segment, which is longitudinally fluted on the dorsal surface (fig. 9) when the anterior margin is contracted by being drawn around the oral cavity, much in the same way as the mouth of a pouch is drawn together by strings; if fully expanded this segment is truncated and the flutings indistinct. The anterior respiratory processes are trumpet-shaped and short; posteriorly the body tapers and the posterior angles of the penultimate segment are produced and carry the tuft of 3 bristle-like hairs characteristic of the body segments. The siphon is short, the tracheal opening being fringed by tufts of long and recurrent setose hairs (fig. 11).

Pupa (Plate XLVII, figs. 4, 5).—The pupa is brown in colour, the hard cuticle being transversely rugose and bearing the lateral hair-tufts of the larva; in outline it is club-shaped, being strongly arched dorsally and tapering posteriorly to the respiratory siphon; the ventral surface is flat. Length, 10 mm.; greatest breadth, 4 mm.