APATURA IRIS. 43 



crown with a pair of long forked, tapering horns, blunt 

 at their tips, curved on their inner sides and concavely 

 bent a little in front, and covered with raised points on 

 their front surfaces. They are much like those of a snail, 

 but not retractile or moveable, though when the head 

 is rapidly in action, as is the case in feeding, the horns 

 are displayed perpendicularly, or sloping backwards 

 and forwards ; but they are horizontal when the larva 

 is at rest or in alarm. The crown is slightly notched 

 and the face rather flattened above, but a little convex 

 towards the lower part where it is widest. 



"When full grown and stretched out the larva attains 

 the length of two inches, is rounded, and tapering to- 

 wards both head and tail, the anal segment terminating 

 in an elongated, rather flattened point, which is, how- 

 ever, divided and slightly forked at its extremity ; the 

 prolegs short and thick, with a fringe of short hairs 

 above them along the sides ; the segments are sub- 

 divided into five portions, the anterior being much the 

 widest, and all are studded with rows of minute raised 

 points. 



When the larva is alarmed the segmental divisions 

 and deep subdivisions disappear as it suddenly con- 

 tracts its length, and are all drawn up so closely to- 

 gether as to make the raised points resemble the pile 

 of a rich velvet ; at such times, and when at rest, the 

 head is bent down, the horns appear in a line with the 

 body, the back much arched, thickened, and rounded, 

 remaining a long time motionless, assimilating admir- 

 ably with the leaf on which it rests. It reposes on a 

 leaf, generally on the under side, but not invariably so, 

 and spins a quantity of silk, to which it firmly adheres. 



In colour the larva is a bright full green on the back 

 and sides, as far as the sixth segment, then blending 

 gradually into a yellower green, with the three last 

 segments much paler; the whole surface is studded 

 with minute yellow points. 



On the back of each horn, and extending along the 

 second, third, and fourth segment, is a subdorsal stripe 



