74 HETEROGENEA ASELLUS. 



measured about half an inch long, and a quarter of an 

 inch broad across the middle of the body, whence it 

 tapered towards each end ; but in repose, or when dis- 

 turbed, its length did not exceed three-eighths of an 

 inch, as the head and the second segment were then 

 entirely retracted, so that the front part of the body- 

 appeared but little tapered, and broadly truncate, 

 though somewhat rounded. When protruded, the head 

 was seen to be very small, and rather flattened as in 

 the Lycdenidx ; the anal extremity was rounded ; viewed 

 sideways the back appeared somewhat arched, and the 

 ventral surface was in close contact with the leaf. The 

 segments were not marked in the usual way by trans- 

 verse folds, but only by narrow dimpled depressions ; 

 there were also little circular dimples on the back, one 

 in the centre of the front of each segment, and two at 

 the back in the subdorsal region ; this region, being a 

 little raised on each side, formed a slight dorsal hollow. 



The six anterior legs, though minute, were yet dis- 

 tinctly to be seen when the larva was in motion, but 

 no ventral or anal legs were perceptible, and instead 

 of them it had along the sides on the margin of the 

 belly, which was deeply depressed along the middle, a 

 soft projecting ridge of extremely flexible skin. This 

 served very well the purpose of legs by its undulatory 

 movement from behind forwards ; one wave at a time, 

 formed under each segment, slowly advancing and 

 subsiding in regular succession as far forwards as the 

 fifth segment. 



The head was smooth and shining, the back and 

 sides rather so, though the skin there was covered 

 with a pubescence, but this was so fine as to be 

 seen only with a powerful lens ; it was noticeable that 

 the dimpled spots were for the most part paler than 

 the rest, and that a few short and very minute bristles 

 were scattered at each extremity, and at intervals 

 along the back. 



The ground colour was a pale yellowish-green, 

 watery looking along the sides, where it soon faded 



