With slight exception, we find no homogeneousness in the perfect state of the insects of this group, but much variation of form presented by the different species. The general shape of the body varies from one greatly elongated, as in Metura elongata, to a short and robust as well as to a short and slender form. In like manner the wings vary from a long, narrow, and sharp-pointed wing, as in Metura, to those of short, broad, and ample proportions; and, again, may either be densely squamose, 
or colorless, of beautiful hyaline texture, almost or completely destitute of scales or hairs. The antennae may be deeply pectinated only at the base, in others they are feathered to the tip, and in the number of joints offer striking variations. But the males of nearly all Psychidæ are characterized by a uniform dull dark color, of a brown or gray tint; there is an almost total absence of bright color or of pattern. Yet these moths are in nearly all cases day-flying. Probably the beauty of the males disappears when the females become degenerate, and the conditions which produced it are then at an end.
The larval cases of these moths are among the "common objects" in Australia, meeting the eye everywhere suspended to trees and shrubs, such as the different kinds of Leptospernum, Melaleuca, etc., by their anterior end, and swinging loose otherwise. When unusually abundant, so as to look like a good crop of some seed or fruit, the pendent berths are particularly conspicuous, and attract the attention of the least curious of mortals. The most striking examples of the group belong to Metura Saundersii, whose cases are sometimes over five inches long; those of the male are one third smaller.
Considering this abundance, the insects are singularly rare in the moth state; not one case in a hundred will be found to produce a moth, owing partly to the destructive effects of attacks on the larvæ of ichneumonideous and dipterous parasites. From the same cause, nothing is harder, nay, more nearly impossible, than to rear these creatures in confinement; the caterpillars of a species may be collected persistently for years, and watched with incessant care, and yet never reach the perfect stage; hence there are already imperfectly known species of which the more mature conditions await discovery; and when success does attend our efforts at protection, many examples are probably observed of the depredations of the insidious parasites. Not that failure to attain perfection is always due to infesta-
