46 ARKIV FÖR ZOOLOGI. BAND 8. N:0 9. 



so, as the mandibles are quite atrophied; its only function 

 seems to be to spin the cocoon. 



The last instar of this species is, indeed, a very stränge 

 creature and it is not at all surprising that even such a 

 skilled observer as Sich [7, p. 39], as he himself tells us, at 

 first mistook it for the larva of a parasite, and that it revels 

 in a special name, »praepupa», which term is of course very 

 misleading. 



The head and mouth-parts of this instar are very peculiar. 

 In figs. 66 and 67 the former is delineated in dorsal and 

 ventral aspect. 



We notice that a rounded lobe is distinctly set off at 

 the anterior margin of the head, and that this is divided into 

 three portions by a y-shaped line ; it is probable that the 

 median one of these represents the labrum (Ib). In the middle 

 of the dorsal side we notice two longitudinal apodemata 

 represen ting the 2-line, which in many miners (comp. p. 9 — 10) 

 are thus modified; the median portion has a free anterior 

 edge subbilobate, and projecting above the level of the portion 

 in front of it, and has two pairs of hairs, a feature which 

 it shares with the post-clypeus + praefrons of many larvae and 

 whicb, in my opinion, argues for its interpretation as a fused 

 post-clypeus and praefrons. 



There are no eyes nor any antennae to be seen on the 

 dorsal side of the head, and, as a matter of fact, the former 

 are quite atrophied, without any traces of them being left. 



The antennae, on the other hand, are still present sub- 

 marginally on the ventral side (a, fig. 65) although in a very 

 reduced form, being composed of a pair of small, rounded 

 areas, on which two conical sensillae and a hair are inserted, 

 thus recalling the structure of the antennae of Nepticula 

 (comp. fig. 25). 



On the ventral side we notice a pair of longitudinal, 

 parallel apodemata which connect the hind margin of the 

 labial complex with that of the head. 



The submentum is large, with semicircular posterior 

 margin and straight sides meeting forward at a very blunt 

 angle; from the point where the apodemata reach the hind 

 margin of the submentum, a pair of fine lines run forward 

 towards its middle, parallel with the sides; their interpreta- 

 tion is doubtful. 



