markings and attiiiulcs of lepidoptcrom lanue. 818 



of nearly all the larvae observed. Only at this point in 

 the ontogeny are there considerable changes in the 

 larvae, for the first two stages were very similar to each 

 other, and the last two are practically the same as the 

 third. The length is about 11 mm. when the second 

 ecdysis is taking place, and the larva is fairly stout on 

 entering the third stage. It is very difficult to accurately 

 measure the larvae in this and (to a less extent) in 

 succeeding stages, because the body is so rarely extended. 

 The important structural characters of the larva from this 

 time forward concern the head, the 8rd pair of thoracic 

 legs, and the 4th and 5th abdominal segments. The 

 head is much flattened, and appears merely as a con- 

 tinuation of the body, the constriction between it and 

 the 1st thoracic segment becoming quite inconspicuous. 

 The 3rd pair of thoracic legs are placed upon the summit 

 of a very large and prominent transversely-directed ventral 

 ridge. The importance of this structure is to render 

 conspicuous the dorsal bend of the body at the 3rd 

 thoracic segment in the protective attitude assumed 

 during rest. At such a time the head and 1st and 2nd 

 thoracic segments are bent backwards so far as to be 

 almost parallel with the anterior abdominal segments, 

 while the 3rd pair of legs are held straight out from 

 their ridge on the convexity of the abru])t bend in the 

 3rd thoracic segment ; but the extremities of the legs 

 are generally curved inwards so as to nearly meet. 

 The effect is greatly increased by lateral swellings on the 

 2nd thoracic segment, and by the 1st and 2nd pair of 

 legs being bent up towards the head, and thus becoming 

 invisible except on a close inspection. The colours, as 

 will be seen, greatly aid the effect of this extremely 

 irregular and unlarva-like attitude. The protection is 

 by resemblance to a brown and crumpled leaf-fragment, 

 or to the excrement of birds, according to the colour ; 

 and at this stage the larva is generally at rest upon the 

 leaves. The 1st, 2nd, and 3rd abdominal segments are 

 extremely round and cylindrical, and it is difficult to 

 detect the furrows between them. The 4th and 5th 

 abdominal segments are much swollen, and each has 

 two small dark dorsal tubercles terminated by a single 

 hair. These two segments are held in a slight curve 

 with the concavity below. Other similar, but much 

 smaller, tubercles are sparingly scattered over the body 

 of the larva. There are also the two posteriorly-directed 



TRANS. ENT, SOC. LOND. 1885. PART II. (aUG.) Y 



