The caterpillar is glossy, and has a semi-transparent appearance. It is greenish white above, with a darker line down the back; and the sides are of a brighter green. It feeds on the stinging nettle (_Urtica dioica_) during May. _The Garden Pebble_ (_Pionea forficalis_) The same family contains also the Garden Pebble, which is one of the commonest frequenters of gardens, both in town and country. The fore wings are pale yellowish grey with brown markings. The latter include a fine line from the tip to the middle of the inner margin, and another paler one inside and parallel with this, having a dark spot near its centre. The hind wings are lighter, and have a pale and interrupted line parallel with the hind margin. [Illustration: FIG. 213.--THE GARDEN PEBBLE.] The caterpillar is pale greenish, with a dark line along the back and on each side. It feeds on the cabbage and other cruciferous plants. The moth flies from May to the end of the summer, and the caterpillar may be found about midsummer, and again in the autumn. _The Beautiful China Mark_ (_Hydrocampa stagnata_) Our last example of the _Pyralides_--the Beautiful China Mark--belongs to the family _Hydrocampidae_. This small family is remarkable for the fact that its four species spend their larval state in the water, feeding on the under surfaces of the leaves of water lilies and other aquatic plants. These curious larvae live either in cases which they construct for their protection, something after the fashion of the larvae of caddis flies, or quite free in the water, and then they are supplied with special breathing organs that enable them to absorb the oxygen held in solution in the water. [Illustration: FIG. 214.--THE BEAUTIFUL CHINA MARK.] The moth we have selected for illustration is a very common species, and may be seen flying in great numbers in the neighbourhood of ponds during June and July. _The Pterophori_ The members of this remarkable group are easily distinguishable from all other moths by the feathery appearance of their wings, a feature that has gained for them the popular name of _Plume Moths_. Their fore wings are more or less divided or cleft, and their hind wings are generally divided into three distinct feathery plumes. The larvae are hairy, and when full fed they suspend themselves by their anal claspers, and change to the chrysalis state without any kind of covering. They are generally to be found in spring and early summer, but some of them feed in the autumn. The chrysalides are often hairy, though some of them are perfectly smooth. Plume moths are to be met with more or less throughout the year. Many of the earlier species appear on the wing in spring and early summer; but the late feeders emerge in the autumn, and hybernate through the winter, often taking to the wing on the mild days of our coldest months.