32 



ARKIV FÖR ZOOLOGI. BAND 8. N:0 9. 



of the labium, but a little away from it, so that only slightly 

 more than the distal half of it projects beyond the margin. 

 Labrum, mandibles, maxilla3, and above all the hypopharynx 

 are characterized by being richely provided with tufts of 

 filamen ts and narrow, pointed appendages. Thus a t the base 

 of the mandibles (fig. 38) we notice a bundJe of long, flexible 

 filaments, of ten bifurcated at the top; at the upper (inner) 

 side of the maxillae we notice (fig. 46) 6 — 8 transverse rows 

 of narrow, pointed appendages, which increase in length 

 towards the top. If we examine the hypopharynx, we notice 

 that it is excavated in the middle. and that its sides are 

 shaped like well-defined ridges, on the median sidc of which 



Tischeria elcébladella. 



Fig. 50. Labium and top of hypopharynx, ventral aspect. X 300. 



Fig. 51. Palpiger and maxillary palpus, ventral aspect. X 386. 



Fig. 52. Hypopharynx and distal half of maxilla, dorsal aspect. X 223. 



there is a dense row of long, flexible, bifurcate filaments, 

 projecting towards the median line (fig. 47). 



The probable significance of these accessory structures 

 has already been discussed in a preceding chapter (p. 24). 



Tischeria ekebladella. 



The lar va of Tischeria is, as far as ] know, the only 

 leaf-mining larva which makes use of its spinneret and silk- 

 glands during its whole life. 



