2 ARKIV FÖR ZOOLOGI. BAND 8. NiO 9. 



features of theirs, of which we know very little indeed, and 

 this applies particularly to the exteriör and interiör morpho- 

 logy of the Järva?. 



Stainton, for instance, in his excellent »Natural History 

 of the Tineina» [3]., which is a standard work, indispensable 

 to everybody desirous of studying the leaf-miners, pays very 

 little attention to the external morphology of their larva?, 

 and, even if he could not help noticing, that the younger 

 larva? of the gen. Lithocolletis differ in shape from the older 

 ones, all he has to say on that matter is [vol. 2. p. 4.]: »The 

 rather pointed, especially when the larva is young, the 2nd, 

 head is 3rd and 4th segments are generally broader than the 

 remaining ones, the 3rd being the broadest, hence these 

 caterpillars have not a graceful appearance.» 



The following comprises the information regarding the 

 dimorphism and morphology of the trophi of the larva?, 

 which I have been able to gather in the litterature concer- 

 ning them. 



The first to notice it seems to have been Dr. B. Clemens, 

 of America, w T ho, according to Chambers [4. p. 81 — 87], cailed 

 attention to the fact that it is possible to discern two dif- 

 ferent types of larva? in the gen. Lithocolletis, one cylindric 

 and one flattened. The latter he describes as follows [1. c. 

 p. 81]: »The head is thin and flattened, with the mandibles 

 forming an appendage in front; the body is flattened, deeply 

 incised, and mammillated on the sides.» 



Chambers himself made the observation that on the 

 dorsal side of nearly all species of the genus there are dark 

 spöts, varying according to the age of the larva?. According 

 to him there are no intermediate forms connecting both 

 groups, but some larva? of the flattened type during their 

 growth approached the shape of the cylindric type, without, 

 however, entirely assuming it. This applies to L. cincinna- 

 tella Chamb. and A. corylella Chamb. 



Chambers does not deny that a change similar to that 

 observed in these two species may also take place in other 

 species, but he has not yet been able to observe it. He 

 anounces his intention to investigate this problem. 



Ch. also quotes a statement by Stainton in his transla- 

 tion of Clemens' work on the Tineida?: »I doubt much 

 whether we have in Europé anything resembling this second 



