The larval forms of these interesting little creatures are common in our creeks and water-holes, encased in their cocoons or sacks formed of silken strands covered with bits of sticks, leaves, sand or small stones; they may be often noticed floating on the surface or crawling about under the water among the weeds and mud. These are protective coverings, for though the head and front of the thorax, that are projected in front when the larva is moving along, are hard and leathery, the abdominal segments are covered with a thin integument, and would soon fall a prey to the many carnivorous water insects in the ponds if it were not for their case-bearing habits. These cases, unlike those of the terrestrial case moths, are open at both ends, so that the water can flow right through when the creature is crawling about. They are known in England as “water moths,” or “caddis-flies,” and are much sought for by anglers as bait for fly-fishing. The perfect insects have two pairs of membranous wings with fewer cross veins than other members of the Neuroptera; the hind pair are broadest and folded when at rest; most of them are clothed with fine hairs instead of scales. The head is small, with very long, slender, thread-like antennae composed of many short indistinct joints, and the biting mouth is rudimentary; the prothorax is short, with an elongate body rounded at the extremity; and the legs are well developed, and more or less provided with spines. The female deposits her eggs, enveloped in a gelatinous mass, in the water, often carrying them about with her attached to the tip of the abdomen for some time before they are dropped. Some of the smaller species are so wonderfully like small tinead moths, that it takes an experienced eye, aided with a good lens, to pick them out of a box when mixed up with small microlepidoptera; and from their delicate form and small size most of my specimens have not been taken as caddis-flies, but obtained from the leavings of insect boxes of moth collectors. Between the years 1874–80 McLachlan published his fine “Monograph of the European Trichoptera,” illustrated with a great number of very fine drawings; over 500 species are identified and described in this work. According to Howard, about 150 species have been described from North America. McLachlan treats them as an Order in his work, dividing them into a number of families, chiefly based upon the number of spines on the legs, the joints of the palpi, and the ocelli. Judging from my own collection of caddis-flies I should think that Australia is rich in species, but they are a much neglected family and I do not know of a single named specimen in any of our Museum collections.