Pterellipsis, n. gen.—Near Megistopoda, but with aborted wings. Head once and a half as high as long, in profile subhemispherical, covered with bristles which are longest on upper part of the front; eyes oval, situated on sides of head slightly behind the middle, no ocelli; antennæ one-jointed, flattened, elliptical, three-fourths as long as the head, once and a half as long as wide, covered with bristles and bearing a long one at apex. Thorax greatly compressed, strongly gibbous, the sternum flattened; its front end lamelliform and prolonged in front of the anterior coxæ, a longitudinal impressed median line and on each side, slightly behind its middle, is an impressed line extending from its obliquely outward and backward to the lateral margin just behind the middle coxæ wings narrow, projecting obliquely upward and forward, divaricate, once and one-third as long as height of thorax, four times as long as wide, with three veins besides, the costal, each of the median veins forked near the middle, the front fork of the anterior vein reaches the costa near the last fourth of its length, the posterior fork ends in the extreme tip of the wing; the forks of the following vein are united at their apices, and extended obliquely forward, reaching the wing-margin slightly below the tip; a short distance before this union the anterior branch is connected by a crossvein with the posterior branch of the preceding vein; the other vein extends along the posterior margin of the wing neary to its middle, then unites with the posterior fork of the preceding vein; veins bearing several stout bristles; halteres distinct; front femora considerably thickened, their tibiæ rather slender, femora rather robust, once and a third as long as the front ones, their tibiæ as thick as and nearly twice as long as the front ones, hind femora and tibiæ more slender than and nearly twice as long as the middle ones, each femur bearing several bristles, the tibiæ destitute of bristles; first four joints of the front and middle tarsi subequal in length, each slightly broader than long, together slightly longer than the fifth, which is considerably swollen; first joint of the hind tarsi twice as long as wide, as long as the two succeeding joints, the last joint swollen, as long as the three preceding ones; each tarsal claw bears a large lobe at the base of the under side.