I have again to tender my sincere thanks to Mr. Robert Adkin, F.E.S., for kindly lending specimens of rare species and varieties for figuring; and also to Mr. B. Adkin, Mr. G. T. Porritt, F.E.S., and Mr. A. J. Scollick, F.E.S. I desire also to gratefully acknowledge the loan of further beautiful coloured drawings by Mr. Alfred Sich, F.E.S. These figures have been most accurately reproduced in black and white by Mr. Horace Knight, to whom I am greatly indebted for his able assistance in connection with the numerous drawings of ova, larvae, and pupae. In some cases the preserved skin of a caterpillar had to serve as a model, and where this occurs the fact is mentioned. A few figures of larvae have been copied from Dr. G. Hofmann's _Die Raupen der Schmetterlinge Europas_, 2nd edit., by Professor Dr. Arnold Spuler. All such reproductions are duly noted in the text. Mr. Knight is also responsible for the coloured drawings for Plates 1, 13, 36, 61, 96, 98, 100, 104, 134, and 148; the figures on which, except that of _Zygaena filipendulae ab. chrysanthemi_, are from specimens. "A Forester," Mr. H. Main, F.E.S., and Mr. W. J. Lucas, B.A., F.E.S., were good enough to furnish prints of some of their excellent photographs depicting life-history details of moths and caterpillars in repose, as met with in nature. RICHARD SOUTH. * * * * * {1} THE MOTHS OF THE BRITISH ISLES. NOCTUIDAE. TRIFINAE (_continued_). THE HEART MOTH (_Dicycla oo_). A male specimen of the ordinary form of this moth is shown on Plate 2, Fig. 1. Ab. _renago_, Haworth has the space between the central shade and the submarginal line more or less suffused with dusky or reddish grey. An intermediate form (Fig. 2) has a transverse band of darker colour between the second and submarginal lines of the fore wings (ab. _ferruginago_, Hubn.). The ground colour varies from a whitish or straw-yellow to reddish yellow (ab. _rufescens_, Tutt), and the markings are more distinct in some specimens than in others. The caterpillar, which feeds from April to early June on the foliage of the oak, is black above and brownish beneath; there are three white lines on the back, the central one widest and more or less interrupted; the stripe along the black-outlined reddish spiracles is yellowish-white; head, and plate on first ring of the body, black and shining.