In this family there are a number of handsome delicate moths with slender bodies, large flattened wings often toothed round the edges, which when the insects are at rest (usually upon the under surface of leaves) are pressed flat and spread out like a fan against the surface. The caterpillars are slender cylindrical creatures, green or brown in tint and so imitative of the twigs or foliage among which they feed, that it is possible to pick off a branch upon which a caterpillar is resting without observing the creature until it moves; they are furnished with the usual six legs on the thoracic segments close behind the head, and two pairs of abdominal legs near the anal claspers, so that they have legs at each end, and when moving along they draw the hind portion of the body up to the head before the front legs are moved: thus at every step forward the body is arched up into a semicircle, from which habit they are popularly known as “Loopers.” The best method of collecting the moths and their caterpillars is by beating or shaking the low scrub in the early morning; and the latter are very easily bred in captivity if supplied with material from their food plants. These moths are well represented in Australia; most of the earlier species have been described by Walker and Guérin (Proc. Linn. Soc. N.S.W.). Meyrick has classified and described a great number of species of this family in a series of papers entitled “A Revision of Australian Lepidoptera,” which the student will find in the volumes dating from 1886 to 1891. The Genus _Euchloris_ contains a number of beautiful moths with delicate pale green wings frequently marbled with white lace-like tracery. Meyrick (Proc. Linn. Soc. N.S.W. 1887) lists 43 species; and Lower, in his “Catalogue of Victorian Heterocera,” published in the “Victorian Naturalist,” lists 15 as Victorian species; but some of these have a wide range. _Euchloris submissaria_ measures about 1½ inches across the outspread wings; its general colour is rich deep green, with the antennae, front margin of each fore wing, outer edges of both pairs of wings, a central stripe on the thorax and body, and the legs creamy buff white. The caterpillar is of the usual cylindrical form, varying from dull buff to light brown, and it feeds upon the foliage of the black wattle. _Crypsiphona occultaria_ measures nearly 2 inches across the wings, and is of a uniform light greyish brown on the upper surface, very finely banded in irregular circles; but the under surface is pearly white, spotted on the fore wings with black, crimson and brown; the hind ones are banded with brown and crimson. It has a very wide range, and has a habit of resting against weather-worn posts and walls, its outspread wings matching the colour of its surroundings. The larva feeds upon the foliage of the gum trees, and is of a uniform dull green tint, striped down the sides, the head pointed in front; the whole caterpillar looks wonderfully like a eucalyptus twig.