104 THE entomologist's kecoud. 



and taper gradually towards the 10th abdominal, which is bluntly 

 rounded. Beneath the mesothorax there is a transverse ridge or 

 swelling, which seems to be the initial stage of the proleg-like pro- 

 jections which appear in the last instar. The nietathovn\ is similarly 

 furnished, but there is no trace of any such prominence on any of the 

 other segments. Both the meso- and metathorax are swollen dorsally, 

 and the enlarged state of these two segments, aided by the ridges 

 beneath them, no doubt offer a good thrasting-block to the larva while 

 it is feeding, as well as forming, anyhow, part of the means of 

 progression. Segmental divisions very well marked. The colour of 

 the head is very pale brownish-ochreous, and that of the body pale 

 grey. The dorsal canal is light green. Width of head 0-09ram., and 

 the length of the larva is 0-7mm. No setfe were found, though search 

 was made by means of a high objective. 



Second instar: Larva rather flatter than in first instar. The 

 thoracic segments are not so large in proportion to the abdominal, 

 though the prothorax appears wider in proportion in some specimens. 

 The pads beneath mesothorax are more clearly developed than in the 

 first instar, but they are more or less connected by a raised ridge, as 

 are also those on the metathorax. The head is pale brown, with the 

 usual lines darker. The spinneret is very long. The body is at first 

 grey, but becomes later bright yellow. The dark ganglia can be seen, 

 but they are not so conspicuous as in the third instar. The renal 

 organs (?) are easily seen, and yellow in colour. There is a pair of 

 curved grooves situated on the anterior portion of the segments in the 

 subdorsal region. There are no prolegs on the abdomen. The length 

 of the larva is limm. and the width of the head 0*14mni. 



Third instar: Width of head 0'21mm. Length of larva l|-mm. 

 Head pale brown, body bright golden -j-ellow. The pairs of fleshy 

 prolongations beneath the meso- and metathorax are distinctly visible, 

 but there are no abdominal prolegs, although the segments on the 

 venter of the abdomen are very Avell marked, and the rotundity of the 

 first abdominal is less conspicuous than the others. (This segment 

 has no prolegs in the fourth instar.) Some " Bacot's pile " occurs on the 

 venter, and though something like tubercles were observed on the 

 dorsum, no setsB could be discovered. Thus, though the development 

 is comparatively slight, there is a distinct advance towards the active 

 fourth stadium. 



Fourth [last] instar : Width of head O'Smm. Length of larva 

 3'8mm. Head pale yellowish-brown, with the lines and mouth-parts 

 reddish. Prothorax and 10th abdominal segment very pale grey, the 

 other segments yellow, very shining. When in the mine the 

 alimentary canal is seen as a broad green stripe, but after the larva 

 has left the mine, no trace of the green coloration is visible. The 

 head is very broad and very flat, so that its dorsal and lateral aspects 

 are very different. It can be almost entirely withdrawn into the pro- 

 thorax. The spinneret is long, and the antenn;e are conspicuous. 

 There is a very deep notch behind. The prothorax is much wider 

 than the head, and deep!}- divided into two subsegments. The meso- 

 thorax still wider, and also divided into two subsegments, but the 

 division is not nearly so deep, the metathorax wider still, otherwise 

 similar. The abdominal segments are fairly even in width, though 



