They measure up to about ½ an inch in length; are elongate in form with large globular heads, small toothed jaws, and long, slender antennae composed of 20 or more bead-shaped joints which they are constantly moving when they run about. The thorax is formed of three very elongated segments, so that each pair of legs is very wide apart; and in the winged forms the slender oar-shaped wings with very primitive nervures are so far from each other that they have quite a comical look; the abdomen is short, cylindrical, composed of 10 segments, rounded at the tip, with large anal appendages (cerci). The legs are curiously thickened, with the tarsi of the front pair shaped somewhat like a weaver’s shuttle. Until last year they were unknown in Australia, when I described two species (Proc. Linn. Soc. 1904); the first _Oligotoma agilis_, is a wingless form, of which I found two specimens while turning over granite boulders at Bomen near Wagga N.S.W. The second, _Oligotoma gurneyi_, was obtained by Mr. Gurney in a lighted room one evening in a suburb of Sydney; it had well developed wings. Soon afterwards Mr. Steel had his attention called to what one of the men in the Colonial Sugar Co.’s refinery at Pyrmont called a “white fungus” under one of the windows. This Mr. Steel found to be a mass of white web matted with excrement and full of slender brown insects, which he collected into a bottle and handed to me. Though most of them were mature, only a few showed regular wing pads, but otherwise they appear to be _O. gurneyi_; in captivity they spun a great quantity of delicate white web among which they hid, but when wet sugar was placed on the cork they ate it readily. Family 5. Book Lice. PSOCIDAE. These are very delicate little creatures that run about on moss grown fences, tree trunks, among foliage, or hide in boxes, old baskets and other litter. In some groups, while the larvae and pupae are wingless, the perfect insects have two pairs of delicate wings with curious curved transverse nervures and very few cross veins, so that the cells are few. In other groups the perfect insects are wingless, or if present, aborted and useless for flight. They are all furnished with long slender antennae consisting of from 11 to 25 joints; the head is large, rounded in front, with convex eyes, and three ocelli (wanting in the wingless forms). [Illustration: =Fig. 16.=--_Philotarsus froggatti_ (Enderlein). A typical specimen of the Psocidae found near Sydney, N.S.W. (Redrawn from Enderlein’s figure,--W.W.F.)]