prothorax small; mesothorax curved upwards and projecting shell-like over prothorax, with a loose space between neck and pronotum, and a larger one between prothorax and mesothorax. Legs hairy, piceous-black, with two large spines (spurs) at lower end of tibiæ; femora yellow above, brown at lower end; ungues long, diverging and bright red-brown. Wings iridiscent, brownish, finely ciliate with dark hairs, densely reticulated, cells all shapes and sizes, but more regularly rectangular on sub-median vein, and largest between sub-costal and median veins, pilose with long dark and rather distant hairs on all veins and bands; spotted generally with brownish dots and markings, that are somewhat sub-quadrate at bands and triangular at forks (and sometimes broadly so at bands), outer edges irregular and not defined, the centre of the wings free of spots, also the costal cells from base to stigma: anterior wings (each) 1 ½ inches long, 5 lines wide, sub-oblong-lanceolate, dimidiate, much contracted at base, obtuse-pointed at tip, apex inclined below; stigma oblong, whitish-yellow (or light cream-colour) with short dark hairs, a large black-brown spot at the basal end, and a brown blotch opposite between sub-costal and median veins, and another blotch directly opposite towards lower margin; costal vein yellow at base and gradually becoming brown; sub-costal vein double for about two-thirds of length of wing—from ¼ inch from base on to stigma, and without bands between,—yellow with brown dashes at junction of bands, and on sub-median vein below; ante-cubitals straight, simple; post-cubitals forked and sloping, a few in the centre forming cells: posterior wings each 1 ¼ inches long, 4 lines wide, sub-linear-oblong, more acute, and less and more finely spotted than anterior pair; spots mostly triangular in forks below stigma and about tips; stigma rather large, oblong, whitish; a brown blotch opposite stigma and near the lower margin.

Length of the body 16 lines; of the wings extended 38 lines.

Hab. Seventy-mile Bush, Waipawa County; (rare, like other species of the genus; three specimens only obtained with much difficulty); 1882–83; W.C.

Obs. A very elegant insect, in form, colour, iridiscence, and finely hairy and ciliated wings; in this latter respect closely approaching the next sub-order Trichoptera. It seems to have some affinity with our only other and little-known New Zealand species of this very large and cosmopolitan genus,—M. acutus, Walker, (B.M.),—judging from description only; but it is very distinct.

The lerva is ovate, thick, fleshy, largely convex above, 6–7 lines long, 3 lines broad, of a reddish-grey hue, spotted with brown and black. Head 1 line long; mandibles 1 ½ lines long, curved, hairy, grooved on lower surface, each having three large and stout curved spines on the inner margin;