INTRODUCTION. XXXIX 



The head is generally of a uniform colour, but is frequently 

 spotted with white, in which case the antennae are often ringed 

 with white, and the orbits are white. 



The second division of the body is the thorax, which is com- 

 posed of three segments, called respectively the pro-thorax, 

 meso-thorax, and meta-thorax. The lower surface is called the 

 "pectus," and the sides, below the wings, are called the 

 " pleura." The thoracic segments are closely united in 

 Lepidoptera y and bear the organs of locomotion, each segment 

 bearing a pair of legs, and the two hinder pairs the wings 

 also. The scutellum, which is so largely developed in many 

 beetles and bugs, is inconspicuous in Lepidoptera, and has its 

 point directed forwards. 



The pro-thorax is narrow in Butterflies, and in many species 

 it is hardly visible above ; on the under surface it bears the first 

 pair of legs. On the upper surface, when much developed, it 

 is sometimes of a different colour ; thus, in many East Indian 

 species of Papilio and Ornithoptera, it is of a bright scarlet. In 

 such a case it is called the collar. The meso-thorax and meta- 

 thorax are closely united in Butterflies, resembling one solid 

 piece ; the former bears the second pair of legs and the front 

 pair of wings ; and the latter bears the third pair of legs and 

 the hind pair of wings. In front of the fore-wings are two 

 hairy tufts, resting on horny scales, which are called the 

 lappets, patagia, or tegulae. Many Butterflies are spotted with 

 red or white on the head and thorax, and in this case the 

 pleura is likewise spotted, and the antennae and legs are 

 ringed with darker and paler, the under surface of the antennae 

 and especially the tip of the club, and also the orbits, being 

 likewise paler. In some Moths which spin cocoons, a strong 

 spine may be seen at the base of the wings beneath, which the 

 insects use in making their way out. 



The legs, as in other insects, are composed of the usual five 



