lepidopteroiis larva and loupce. 147 



the onl}' instance, as far as I am aware, of the "eighth 

 stripe " gaining a coloured border, the exception being 

 doubtless explained by the fact that this stripe consists 

 of an upper part onl}^ (upon the first abdominal segment, 

 and never extending downwards upon the third thoracic 

 segment), and such upper parts possess coloured borders 

 in the case of A. atropos alone. The shagreen dots 

 form a very remarkable addition to the markings of the 

 adult over the dorsal surface of the abdominal segments 

 (first to eighth, both inclusive). Over an area rigidly 

 limited by the inferior edge of the lower part of an 

 oblique border in each segment the shagreen dots form 

 the centres of relatively large circular patches of purple. 

 These patches are larger upon the borders than else- 

 where, and are especially large upon the superior 

 posterior part of each border. The patches are 

 especially small and scarce posterior to the upper part 

 of the sixth border on the seventh abdominal segment, 

 while upon the eighth abdominal segment there are 

 only a very few faint patches, all of which are placed on 

 the upper part of the seventh border, which traverses 

 this segment. The purple patches have evidently spread 

 from the bases of the dots, which are still visible in the 

 centre of each as a small light spot (which, however, is 

 not raised above the general surface of the larva). These 

 dots have entirely lost the hairs in this last stage, but 

 their former presence is probably indicated by a minute 

 central scar-like point. The patches are also seen to be 

 connected with dots because of their arrangement upon 

 the eight annuli into which each abdominal segment is 

 divided (except the first, which is only divided into six 

 or seven annuli). The occurrence of the dots upon the 

 coloured borders is quite exceptional, but then in this 

 larva the former become the centre of patches of the 

 same colour as the latter, although it is noteworthy that 

 the patches are always purple, while the upper parts of 

 the stripes become blue. It may be that the patches 

 point to the origin of the borders upon which they 

 persist ; but, if so, such a development of this marking 

 is most unusual, for in other forms the borders arise first 

 by the absence of dots, secondly by the darkening of the 

 ground colour, and finally by its replacement by a diffe- 

 rent tint. On the other parts of the larva the shagreen 

 dots are more normal when they are present. Thus 



