1641. LEPIDOPTERA. This well-known and beautiful order is characterised by four wings, thin, membranaceous, and covered with a fine powdery substance; this, on being magnified, is shown to consist of innumerable minute scales, lying one upon another like those on fishes. Their mouth consists of a long and slender spiral proboscis or tongue, with two porrected palpi; and they undergo the changes of caterpillar, chrysalis, and perfect insect. Lepidopterous insects are known in common language by the names of butterfly, hawk moth, and moth, of each of which there are many thousands of species. Few lepidopterous insects are injurious to the agriculturist; but a great number devour, in their caterpillar state, the leaves of trees in the garden, the orchard, and the plantation. A few of these will be noticed under the particular tribes to which they belong.