The caterpillar lives in the flowers of the foxglove (_Digitalis purpurea_) and feeds therein upon the stamens and the immature seeds. It enters by boring through the side walls, and then secures the longer lobe of the blossom to the shorter upper one with a few silken threads. Tenanted flowers have {224} a rather faded look and are easily detected. July is the best month, but the caterpillar may be found earlier as well as later. The moth is out in May and June, and is found in almost every part of the British Isles where the foxglove is common. TOADFLAX PUG (_Eupithecia linariata_). Very similar to the last species, but generally smaller, neater and more glossy looking. The central band of the fore wing is blacker, without ochreous clouding below the middle, and the edges are not wavy. The hind wings are darker, and the only distinct band is a whitish one beyond the middle (Plate 93, Figs. 3, 6). The caterpillar is yellowish green, with a series of dull olive or rust coloured spots or bars along the back, bordered on each side by a dusky olive line; in some examples the markings are absent (Crewe). It feeds in the flowers of yellow toadflax (_Linaria vulgaris_), and may be reared on flowers of the snapdragon (_Antirrhinum_). It is hardly necessary to examine each blossom separately to find the caterpillar, except, perhaps, to make sure when doubtful about the quarry being there. Probably, a handful of the flower sprays gathered in August or September in any locality in the southern half of England where the food plant abounds would furnish moths in the following May or June. The _Linaria_ should be secured on a dry day for choice, but when brought home it need not be put in water; just throw it into an airy breeding cage, and hopefully await emergence of the perfect insects in due course. Sometimes caterpillars attain the moth state the same year. The range of the species in England extends to Durham, but it seems to be rather uncommon from the Midlands northwards. It is found in Wales, and has been recorded once from Scotland (Inverurie), and once from Ireland (Dublin). {225} MARBLED PUG (_Eupithecia irriguata_). The fore wings are whitish and rather shining, the discal spot is black and very distinct, but the dark grey-brown markings, which are only well defined on the front and outer marginal areas, vary in intensity (Plate 93, Fig. 9). The long, slender and roughened caterpillar is dull yellowish green; three lines along the back, the central one reddish and expanded on the middle rings, the others yellowish; head, reddish. It feeds on oak, in late May and in June. The moth is out in April and May, and is sometimes found on fences or palings in the neighbourhood of oak woods, but may be jarred from the oak boughs, on the undersides of which it usually sits.