When quite fresh, this moth (Plate 43, Fig. 1) is exceedingly pretty; the pale blotches vary a little in size, as also do the reddish marks upon them. The caterpillar adorns itself with particles of its food as soon as it leaves the egg in July; after hibernation it uses the scales or husks of the oak buds for the same purpose. When stripped of its trappings it is found to be reddish brown in colour, with three slightly darker lines along the back; hooded bristles arising from raised brownish spots afford means for the attachment of the masquerading outfit, each moiety of which is covered with silk on one side before being placed in the required position. When beating oaks for larvae in May and June, the contents of the umbrella or beating tray should not be too hastily thrown away, but allowed to remain therein for awhile, and closely watched for any movement among the litter. The spectacle of a cluster of oak bracts suddenly becoming active will certainly arouse curiosity, and on examination the cause of the commotion will frequently be found to be the caterpillar of this species. (Plate 41, Fig. 2; after Auld.) The moth is out in June and July, and flies at dusk in and around oak woods. In the daytime it may be jarred from its perch in oak trees, and once I found a specimen on a fence in the Esher district. It has been known to visit light, and examples of a September emergence have been recorded. As a British species it only inhabits England, and it has been noted from Staffordshire and Leicester, but seems to be rare in the midland counties generally. It is more frequently found in the southern and eastern counties. Abroad, the range extends through Central Europe to Southern Sweden, S. Russia, N. Asia Minor, and Andalusia. {105} THE ESSEX EMERALD (_Euchloris smaragdaria_). In some examples of this species (Plate 43, Figs. 2, 3) the green colour is brighter than in others, and very occasionally it is tinged with bluish; typically, there are white cross lines on the fore wings, but the inner one is not infrequently absent, and more rarely both are missing. The white central spot is very rarely absent, and the edges of the fore wings are yellowish. The caterpillar feeds on the sea wormwood (_Artemisia maritima_), and adorns itself with fragments of its food plant in much the same manner as that of the species last referred to. Although obtained in the autumn in some numbers from its food plant, it seems to have been rarely met with in the spring after hibernation. It is, therefore, advisable to collect the caterpillars about September, and transfer them to plants of the garden _Artemisia abrotanum_, locally known as "Southernwood," "Old man," or "Lad's love," or, where available, wormwood (_A. absinthium_) will suit it admirably. Upon either of these plants the larvae will hibernate, feed up in the spring, and become full grown about May. The early stages are figured on Plate 42, larva and pupa from photos by Mr. H. Main.