214 



INTRODUCTION TO ZOOLOGY 



The head bears, besides the proboscis, two large 



compound eyes, often a pair of simple eyes as well, 



and two long many-jointed antennae club-shaped and smooth 



in butterflies (see Fig. 144, a, 6, and c), tapering to a point 



and feathered in moths (see Fig. 144, d, e, /, and g). 



The metamorphosis is complete and very strik- 

 * n ' ^^ e l arva l stage is known as the Caterpillar, 

 and it displays externally, even when full grown, 

 no signs of the organs which appear in the imago, some of 

 these becoming first apparent at the last change of skin 

 immediately preceding the pupal stage. The Pupa is covered 

 by a firm outer skin or shell, formed from a chitinous secretion 

 which hardens its surface. 



The Lepidoptera are conveniently divided into two large 

 sub-orders the Butterflies and the Moths. 



Butterflies (Rhopalocera). 



In Butterflies the antennae are long and usually club- 

 shaped, or are thickened just before the tip. In some of the 



latter cases, the actual tip 

 turns over to form a little 

 hook (Fig. 14 4, c). The 

 antennae are not hairy, 

 except occasionally at the 

 base. The form of the 

 antennae is one of the dis- 

 tinguishing marks be- 

 tween Butterflies and 

 Moths, but the general 



appearance and 



of 



FIG. 144.-Anten,ae of Butterflies and 



a, Large White Butterfly;' 6, Purple Emperor the tWO groups also differ ; 

 Butterfly; c, Large Skipper Butterfly; d, butterflies have slighter 



Buff Tip Moth ? ; d', Buff Tip Moth <j ; bodies and are more 



e, Grass Eggar Moth ; /. Emperor Moth ; , . , , , 



g, Bumet Moth. brightly coloured as a 



rule. They fly by day, 



and when at rest the wings are in most cases held vertically, 

 though there are exceptions to this. The caterpillars of the 

 two groups are alike in general structure, but those of 

 butterflies pupate above ground. (Compare with Moths, 

 p. 228.) 



