4 SOUTH-AFRICAN BUTTERFLIES. 



formation of the beak-like proboscis (rostrum), the Lepidoptera exhibit 

 a remarkable suppression or abortion of all the organs except the 

 maxillas, which are greatly lengthened and so shaped as together to 

 form a tubular "trunk" (JiausteUum), capable of being rolled up spirally 

 when not in use. 



II.— THE ORDER LEPIDOPTERA. 



From what has been stated above, it will be apparent that the 

 Butterflies and Moths belong to the higher or more specialised Insects, 

 distinguished by a more concentrated nervous system, and accompany- 

 ing compactness and very distinct partition of the three regions of the 

 body, as well as by the complete metamorphosis they undergo. From 

 the latter character, the five Orders Hymenoptera, Lepidoptera, Diptera, 

 Neuroptera, and Coleoptera, constitute a Sub-Class named Mctcibola. 

 The following may be regarded as the distinguishing features of the 

 Lepidoptera, viz. : — 



(a.) Imago (or Perfect Insect). 



Body and limbs clothed with scales and hairs. 



Head with the labrum, mandibles, and (except in some of the 

 lower Moths) maxillary palpi, rudimentary ; but with the maxillte 

 elonsrated and modified into a tubular haustellum ; labium much 

 reduced, but the labial palpi moderately developed and laterally com- 

 pressed, forming a protection to the haustellum when coiled up. The 

 lateral compound eyes large and prominent ; two simple eyes (stem- 

 mata) on the vertex in some groups. Antenna3 many-jointed, very 

 variable in shape and structure, inserted on upper part of head, between 

 compound eyes. 



Thorax very compact and robust ; its first segment (jjrotTiorax) 

 very small, bearing the first pair of legs ; its second segment {meso- 

 tliorax), bearing the first pair of wings and second pair of legs, much 

 enlarged, and coustituting the mass of its bulk; its third segment 

 (metathoraoc) small, bearing the third pair of legs and second pair of 

 wings. Prothorax also bearing dorsally a pair of small, horny, scale- 

 like organs (jKitagia) ; mesothorax bearing laterally, immediately 

 above the bases of the fore-wings, a pair of similar appendages (tegulce 

 or pfcrygodes). Wings very large, exceptionally broad, not folding 

 (except longitudinally in the hind- wings of many, and the fore-wings 

 of a few Moths), clothed with scales both above and beneath. Legs 

 short and weak, little used for walking (especially the first pair, reduced 

 to atrophy in many Butterflies) ; the coxae immovable, solidly affixed 

 to the thorax ; the middle and hind tibige armed with a pair of spurs 

 at their extremity, and the hind ones (except in the typical Butterflies) 

 with a second pair rather beyond their middle ; the tarsi five-jointed 

 (except in the fore-legs, when much atrophied). 



Abdomen composed of eight or nine segments, sub-cylindrical, 



