28 [February, 



than those of argus, even more than half as long again. The 

 disposition of hairs and lenticles is almost identical in the two species, 

 but the prothoracic plate has a rather different outline, and argus has 

 lenticles on the 8th abdominal segment that appear to be missing in 

 argyrognomon. 



Fig. 12 shows the dorsum of the prothorax of the larva (full grown) of 

 damon (X30). The prothoracic plate is well in focus, and the stellate hair 

 bases are well seen, and the round bases of the special angular hairs. The 

 crowding of the hair bases elsewhere is great, and is equally seen in Fig. 13, 

 the 7-10th abdominal segments of the same larva. Fig. 13 shows the spiracles, 

 honey-gland, and position of fans. The hairs are not well seen in either photo- 

 graph. Figs. 14 and 15 show the honey-gland of the same larva ( X 114). Fig. 

 14, focussed for the surface, showing the crowding of hairs and lenticles round 

 the margin of the gland. Fig. 15 is focussed deeper, so that the four circles 

 in the bottom of the gland are well seen. I have supposed these circles to be 

 tubercles I and II modified, but whether they are actually glandular structures 

 I do not know. 



Figs. 16 and 17 show the ends of the full-grown larva of argyrognomon, 

 (X30). Compared with the same parts in damon (figs. 12 and 13) there are 

 present dorsal, supra- and sub-spiracular hairs of large size (0"5 and 06 mm. 

 long) which are absent in damon, but the numerous small hairs are, as judged 

 by their stellate bases, smaller and less numerous. The four circles in the 

 honey-gland are very obvious. 



Fig. 18 is the honey-gland (X 114) from the same specimen as fig. 17; it 

 exhibits the hair bases and lenticles around the gland, and the four circles at 

 the bottom of the cavity. 



Fig. 19 is an enlarged view of a pro-leg of a full-grown larva of argyro- 

 gnomon. There are an anterior and a posterior set of hooks, each in two rows ; 

 the central soft extensile pad is well seen. 



I was very interested to find in Scriba's Beytrage (1790-1793) 

 that the two larvse I am describing now were also dealt with, practi- 

 cally together, by Chr. Ph. Pezold (who died in 1797) and are figured 

 together on his PI. XV. The figures are not very good, but the 

 descriptions and histories of the larvse are excellent. About A. damon 

 he says that the larvse are found on Sainfoin, usually on the stems 

 near the root, but came up into the plant to feed morning and evening, 

 leaving the ribs and under cuticle of the leaves. These skeletonised 

 leaves, and the ants that affect the same plants, and often com- 

 pletely cover the larvae, make it easy to find them. He says that 

 Esper had observed that this occasionally occurred with the larvse of 

 icarus. In 'Fuessly's Magazine (1785) one also reads that the larvse 

 of argus are covered with ants, which in no way interfered with their 

 wellbeing. 



