This species, often referred to as _Limacodes testudo_, and said to be the _avellana_ of Linnaeus, is an inhabitant of oak woods, and occurs in Hampshire, Sussex, Kent, Essex, Suffolk, Oxfordshire, Bucks, Gloucestershire, and Worcestershire. A male and two females have been reported from Clonbrock, Co. Galway, Ireland. THE TRIANGLE (_Heterogena asella_). The fore wings of this little species (Plate 153, Figs. 4 [male] and 5 [female]) are of triangular shape; in the male, which sex is smaller than the female, they are dark brown, sometimes almost blackish (ab. _nigra_, Tutt), and those of the female yellowish brown varying to ochreous yellow (ab. _flavescens_, Tutt). The hind wings of the male are blackish, and of the female clouded with blackish. The curious woodlouse-shaped caterpillar is green, sometimes inclining to yellowish; the broad reddish band on the back broadens out before the middle, thus giving the idea of a rough cross, or, as sometimes described, a blunt spear head. It is found, by searching, in August and until October, on the foliage of beech and oak. Birch has also been mentioned as a food plant, and on the continent it is said to feed on poplar, lime, hazel, and hornbeam. Fig. 2 on Plate 149 is from a photo by Mr. H. Main. Although the caterpillar constructs its gall-like cocoon on a leaf or in the fork of a twig in the autumn, it does not change to a chrysalis until late in spring, sometimes not until June. The moth is out in June and July and flies in the sunshine, chiefly in the afternoon, and might easily be confused with the Lechean Tortrix (_Ptycholoma lecheana_). [Illustration] 2 Pl. 150. 1, 2. GOAT MOTH. [Illustration] 2 Pl. 151. GOAT MOTH: _caterpillar, chrysalis and cocoon_. {347} The species appears to be very local in England and confined to the south. Its chief haunts seem to be in Bucks, where it is not uncommon in beech woods at Marlow, and in Hampshire, especially parts of the New Forest. It has been found in Epping Forest, Essex; rarely in Abbot's Wood and Rewell Wood, Sussex; also recorded from Bickleigh Vale and the Plym Valley, Devonshire. The range abroad extends to Amurland. COSSIDAE. [Illustration: FIG. 20. GOAT MOTH AT REST. (Photo by Hugh Main.)] Of the eighty-six Palaearctic species referred to this family, by far the larger number are eastern, only about eight appear to be found in Europe, and but three of these occur in Britain. Meyrick separates _Cossus cossus_ (_ligniperda_) from our other two species, adopts _Trypanus_, Rambur, as the generic name, and removes it to the Tortricina as a family of that group under the name Trypanidae. THE GOAT MOTH (_Cossus cossus_ (_ligniperda_)).