4 
SOUTH-AFRICAN BUTTERFLIES. 
formation of tlie beak-like proboscis {rostrum), the Lepidoptera exhibit 
a remarkable suppression or abortion of all the organs except the 
maxillaSj which are greatly lengthened and so shaped as together to 
form a tubular "trunk" {haustellum), capable of being rolled up spirally 
when not in use. 
II.— THE OKDER 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 Metabola. 
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 maxillee 
elongated 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. Antennse 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 (jirothorax) 
very small, bearing the first pair of legs ; its second segment (meso- 
tJiorax), bearing the first pair of wings and second pair of legs, much 
enlarged, and constituting the mass of its bulk ; its third segment 
(metatJwrax) small, bearing the third pair of legs and second pair of 
wings. Prothorax also bearing dorsally a pair of small, horny, scale- 
like organs (j)atagia) ; mesothorax bearing laterally, immediately 
above the bases of the fore-wings, a pair of similar appendages (tegulcB 
or pUrygodcs). 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 coxse immovable, solidly affixed 
to the thorax ; the middle and hind tibise 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. 
