vi European Butterflies axd Moths. 



citlier in both sexes or in the male only. In such cases the legs are rather smaller, and the tarsi 

 are terminated with a simple horny hook instead of the usual pair of claws ; or the tarsi are either 

 not jointed at all, or only imperfectly (Fig. 30), when they often appear to be united with the 

 tibis into a densely hairy brush-like paw, or the fore-legs are reduced to very small three-jointed 

 appendages. The hind-legs of the male are shortened in a few Hcpialida and Geomctrce. 



The ^vings consist of two larger fore-wings and two smaller hind-wings, so connected together 

 that the hinder edge of the former laps over the front edge of the latter. There are two additional 

 lobes at the base of the hind-wings above in the males of some Geomctrce, which makes them 

 appear as if they had six wings, whereas the wings of the females of many moths are either absent 

 or rudimentary. The wings are formed of a transparent or semi-transparent membrane, which is 

 held expanded by hollow horny tubes called veins, nervures, or nervules, and are covered on both 

 sides with coloured scales, and more rarely with hair-like scales. In some cases the wings are 

 transparent in the centre, being only thinly clothed with scales on emerging from the pupa, which 

 are lost almost immediately. The only European species which exhibit this phenomenon to any 

 remarkable extent belong to the smaller Sphingidce and groups allied to them. The form of the 

 wings is usually triangular, and there are therefore three borders — the front edge, ox casta (Fig. 31, \'R), 

 nearest the head of the insect; the inner margin (Fig. i\,JR), which is opposite to it, and is parallel 

 to the body in the hind-wings; and the hind margin, or border (F"ig. 3i,5w), which lies furthest 

 from the body, and unites the costa with the inner margin. The point where the wings are 

 attached to the body is called the base (Fig. Z\,W) ; the angle formed by the costa and the hind 

 margin is called the tip, ape.x, or anterior angle (Fig. 31,5/) ; and the angle formed by the hind 

 margin and the inner margin is called the hinder angle (Fig. 31, JW), or, in the hind-wings, the 

 anal angle (Fig. 31, ^ W). 



The shape of the wings depends on the comparative length of the margins. The costa is 

 the longest margin of the fore-wings, and their breadth depends on the length of the hind 

 and inner margins taken together. If the hind margin is short, the wing must be narrow ; 

 and the shorter and more oblique it becomes, the narrower are the fore-wings, and the more 

 obtuse is the hinder angle. Sometimes the latter is quite straight, and in some Tincina 

 especially the hind and inner margins pass into each other so gradually that they cannot be 

 distinguished. The breadth of the hind-wings depends chiefly on the length of the inner 

 maro-in, which generally extends as far as the abdomen, or beyond it in broad-winged species 

 such as Butterflies, Boinhyces, and many GeomctrcE. In the other groups it does not extend so 

 far, sometimes only as far as the first segment of the abdomen, and in such cases, also, it 

 generally passes imperceptibly into the hind margin. The triangular form of the wings is thus 

 often converted into a long oval or lancet shape, especially in Micro-I.epidoptcra. The fore- 

 wings are often widened close to the base by a strong curve in the marginal nervures, or the 

 hind margin of the hind-wings is considerably curved beyond the middle. In this case the 

 wings assume, more or less, the shape of a long quadrangle, truncated behind. In the Plume 

 Moths, the wings are divided into distinct feathers almost from their base. In the ordinary 

 Plume Moths {Ptcrop/ioridce), the fore-wings are divided into two feathers, and the hind-wings 

 into three. In the Twenty-plume Moths {Atiicitidcc), each wing is split up into six distinct 

 feathers. 



The costa and hind margin seldom exhibit anything remarkable. The former is generally 

 somewhat curved in the fore-wings, and sometimes more strongly at the base. It is frequently 

 flattened or curved upwards in the middle, and in a few Tortriccs, called " Notch-Wings," it is 

 more or less excavated. The middle of the inner margin of the fore-wings is furnished with a 



