THE LEPIDOPTERA. 289 



are inserted upon the membrane of the wing by a 

 slender stalk, but towards the apex they become more 

 or less widened, usually acquiring somewhat the form 

 of a battledore, although in this respect they vary 

 greatly even on different parts of the same insect. 

 They are not only beautifully coloured in many of 

 these insects, but very frequently, minute as they are, 

 their surface is traversed by numerous excessively 

 delicate lines or striae, by the action of which upon 

 the light the splendid metallic tints exhibited by many 

 butterflies are produced. In most of the Lepidoptera 

 they are placed close together and lie over each other 

 like the tiles on the roof of a house, whilst in some 

 cases they are rather more scattered or even entirely 

 wanting on particular portions of the wings. Besides 

 these scales, the wings are often clothed, especially 

 towards the base, with a few longish hairs, and their 

 margins are frequently fringed in the same manner. 



The head is freely attached to the front of the 

 thorax by a slender neck ; it bears a pair of long an- 

 tennae, a pair of large compound eyes composed of 

 numerous facets, and frequently also, a pair of ocelli, 

 but the latter are usually concealed amongst the hairs 

 with which the head is always thickly clothed. The 

 thoracic segments form a compact ovate or roundish 

 mass, which is generally well covered with longish 

 hair, as is also the abdomen in most cases. The legs 

 are rather long ; the tibiae are spurred at the apex, 

 and the posterior pair frequently furnished with a 

 second pair of spurs towards their middle ; and the 

 tarsi are almost always composed of five joints. 



Such is the general structure of the Lepidoptera in 

 their perfect condition, but in their preparatory states 

 they present a very different appearance ; in fact, there 



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