The Zoologist— March, 1871. 2615 



by. It is true Hartig describes it as " nicht haiifig," but he is 

 speaking of the imago, as he was not acquainted with the larva: 

 with regard to the former I admit that it is but seldom observed. 

 I have never seen the eggs of this species; but, judging from the 

 marks in the petioles of leaves on which very young larvae were 

 living, I consider I am pretty accurate in stating that the egg 

 IS concealed in a little excavation in the leaf-stalk. In the last 

 week of August I found a larva on the leaves of the common alder 

 {Almisglutinosa); it was not more than a couple of days old, and 

 had the appearance represented at fig. 1 (natural size) : it was 

 resting on the edge of elliptical spaces eaten out of the leaf, 

 a a, fig. 2. It held on to the leaf by the six thoracic legs, and was' 

 particularly active in transferring itself to the side of the leaf away 

 from the person observing it : the legs remained quite, or almost, 

 without change of place, but solely by a movement of the body it 

 was placed on the unobserved side of the leaf. If the leaf were 

 then observed from the opposite side, the larva placed itself, 

 without apparent exertion, on the side turned away from the' 

 observer. The young larva, not more than a few millimetres 

 long (represented, magnified, at fig. 3), was dark green on the 

 back, having the sides, the ventral surface and the tail pale green. 

 The head was sordid black, and had on each side a round black 

 spot, in which the eye was situated. The six thoracic legs were 

 blackish at the base, becoming paler towards the claws. I counted 

 twenty legs in all. The body was strongly wrinkled on the back, 

 chagrined with extremely minute spinous points, and the anal 

 valve (fig. 4, highly magnified) was divided by five incisions into 

 six projecting points. 



Fourteen days later this larva had obtained the size of fig. 5. It 

 now curled up the acuminate posterior extremity of the body, 

 more tightly than ever, under the ventral surface, and ate longer and 

 more especially broader strips out of the alder leaves, as repre- 

 sented at b in fig. 2. The head was now pale brown, and the back 

 no longer spinous, but pretty strongly wrinkled, and olive-green. 

 The sides of the body, the ventral surface and the terminal 

 extremity were bluish green. 



When the larva has attained this size, and has, probably, under- 

 gone its third moult, it usually quits the leaf, which had hitherto 

 served it as a dwelling-place as well as for food, and, selecting a 

 fresh leaf, undergoes a change of skin, and, at the same time, alters 



