INTRODUCTION* 3 



the meso-thorax, at its hinder extremity, is observable a 

 small triangular portion called the scutellum, with its apex 

 directed forwards. The Wings, which are inserted in the 

 upper part of the sides of the thorax, are always four in 

 number ; and are composed of a double, thin, transparent 

 membrane, enclosing, and supported and extended by, nume- 

 rous rigid, horny nervures. They are clothed with over- 

 lapping scales, planted by their bases in the membrane 

 of the wing ; and these give to the insects their exceeding 

 beauty of colour. At the base of the forewings, fixed to 

 the meso-thorax, are two scale-like appendages, clothed with 

 hairs or scales similarly to the rest of the thorax, known as 

 tegulce, pterygodes, or wing-covers. The Legs are fixed to 

 the sternum or lower portion of the thorax, and are (as in all 

 true Insects) six in number, a pair on each segment. They 

 are composed of five distinct portions ; the coxa, trochanter, 

 femur, tibia, and tarsus. The coxa is the basal joint united 

 to the sternum ; the trochanter, a minute piece joining the 

 coxa to the femur, or thigh, which is usually the thickest 

 part of the limb ; the tibia, or shank, is more slender than 

 the thigh, and possesses one or two spines at its tip, and 

 occasionally one at its centre ; the tarsus, or foot, is five- 

 jointed, and terminated by two small hooks. The Abdomen 

 is the seat of the intestines and generative organs ; and con- 

 sists of nine more or less retractile segments ; it is commonly 

 sub-cylindrical, smoothly pilose, and occasionally tufted at 

 its extremity. 



The LARVAE of Lepidoptera are elongate, commonly cylin- 

 drical or sub -cylindrical, and composed of thirteen segments 

 or annulations, including the head. The whole insect, with 

 the exception of the head and legs, is of a soft structure, and 

 flexible in the highest degree. The nature of their covering 

 varies considerably : some are smooth and entirely devoid of 

 any cutaneous appendages ; others are dotted with tubercles 

 from which spring stiff bristles or bunches of hair ; some 

 are densely and universally hairy; others with simple or 

 branched, sharp, rigid spines. The Head is divided into two 

 lobes by an impressed line or slight channel running verti- 

 cally ; it is hard, sometimes smooth and polished, sometimes 

 granulated. The eyes are not compound as in the Perfect 

 Insects, but consist of a few simple, hard tubercles, similar 

 to the ocelli of the Imago, and are arranged in two small 

 circles on the side of the head. The antennae are small and 

 inconspicuous, inserted just within the eyes, and composed of 

 three or four joints. The mouth is furnished with a pair of 

 strong, horny, toothed jaws or mandibles, immediately below 



