82 INSECTS. 



Heterocera implies, furnish us with far greater variety in the form of the antennae ; 

 quite apart from the fact that they differ in both sexes of the same species, thread- 

 like, for instance, in the female, pectinate in the male sex, we find at least ten 

 different forms of antennae amongst members of this section : Filiform, or thread- 

 like, gradually tapering to a point ; fusiform, broadened from the base onwards 

 to the tip, which is again narrowed ; dilate, narrow from the base to about one- 

 third its length, then rather suddenly enlarged, and again narrowed at the tip ; 

 ciliate, clothed with the finest hairs ; setigerous, each joint furnished with a bristle 

 on either side ; setigerous and ciliate, furnished with both fine hairs and paired 

 bristles ; fasciculate, each joint furnished with a group or tuft of short bristles, 

 like a small brush ; dentate, or toothed, each joint produced into a sharp tooth-like 

 process at the side ; lamellate, where each joint is produced at the margin into a 

 small plate-like prominence; serrate, sawlike, each joint produced into a short 

 sharp point at the side, giving the whole antennas the appearance of a saw, the 

 teeth are not so long as in the dentate antennae; pectinate, each joint furnished 

 with long plume-like hairs, or a pair of such on either side. 



Thorax and its The second division of the body, like that of the Hymenoptera, 



Appendages. j s composed of three closely united rings, each bearing beneath a 



pair of legs, while the posterior pair carry also on their upper or outer sides, each a 



pair of well developed wings. The prothorax bears the 

 fore-legs. The mesothorax the mid-legs and fore-wings. 

 The metathorax the hind-legs and hind-wings. The 

 legs are not used normally for walking, but are chiefly 

 serviceable for clinging to objects while settling or at 

 rest. They do not call for any special mention ; and 

 are not of great account for purposes of classification, 

 except in the butterflies, where in the case of the males 



a, b, c, h, indicate the normal of the three families Nymphalidw, Erycinidw, and 

 position of the transverse Lyccenidcv, the fore-pair are much reduced in size, 

 bands. , costal margin ;/ being in some cases almost rudimentary. 



inner margin ; d, discoidal * 



spot ; e, reniform spot. By far the most important structure in the eyes of 



the general naturalist, though not necessarily so in 



the opinion of the expert, are the beautiful membranous, scale -clad pinions. 

 These give the distinctive character to lepidopterous insects, and render them so 

 fascinating to the lover of nature. Broad and ample on the whole amongst the 

 butterflies, more narrowed as a rule amongst the moths the hawk-moths for instance 

 they are formed of the finest transparent membrane stretched out between the stiff 

 rib-like nervures, or, more properly speaking, veins, which carry the nutritive fluids 

 from the central system to all parts of the structure. The nerves, as custom will 

 persist in terming them, in the butterflies take a bow-like or ellipsoidal sweep from 

 the base of the wing, forming what is called the discoidal cell, whence there branch 

 off to the edges a series of horizontal, almost parallel, slightly divergent, nervures. 

 On the position of these the identification of species is most securely based, though, 

 in order to examine them, the insect must be spoiled as a specimen. In the moths, 

 on the other hand, the discoidal cell is less conspicuous, though nervures branch off 

 divergently from the base of the win^ in a somewhat similar manner to those of 



LEFT FOBE-WING OF A NOCTUA 

 MOTH. 



