38 LEPIDOPTERA. 



clidissima, Pruneto7'um, Plagicolella, AnguUfasciella, Ru- 

 Mvora, Myrtillella and Ih'imaculella, and have found that 

 this always takes place where the mine, which at first forms 

 a very fine, hardly perceptible track, expands and assumes 

 the later form which characterizes the mine. Thus the larva 

 of Plaglcolella moults at the place where the mine expands 

 into a spot, and on the other hand the larva of Prunetorurriy 

 the mine of which at first forms a closely-wound spiral line, 

 moults exactly at the spot where the mine removes from the 

 so-formed blotch. In general, also, the excremental track is 

 altered after moulting, and becomes broader or looser, or is 

 deposited in curved, transverse lines. The moulting takes 

 place thus: — The old skin cracks at the head, and the larva, 

 continuing to eat its way forward, gradually creeps out of the 

 old skin. 



In larvae in the act of moulting of S'plendidissimella, An- 

 gulijasciella, Rubivora, and, if I am not mistaken, of Tri- 

 maculella, I was astonished by an extraordinary marking, 

 which the larvae had neither before nor afterwards. The 

 colour itself was dirty-yellow ; and on the back was a row 

 of oblique quadrangular dark spots, which gave the larva 

 the appearance as though it were decayed and spotted, 

 although the regularity of the markings startled me. As 

 the larva then gradually crept out of its old skin, these spots 

 remained in their place, and the pale green or pale yellow 

 larva, which had assumed a fresh colour, no longer showed 

 any trace of them. More frequently the spots moved, as 

 well as the old head, a short distance forward with the larva, 

 but the row did not always remain complete, and no longer 

 so decidedly along the back of the larva ; but as this in eating 

 turned to the side and so took up a curved position, the 

 green dorsal line in AnguUfasciella and Rubivora was per- 

 ceptibly at the side of the row of spots. Afterwards the 

 spots became lost in the excremental track. Hence it 



