20 THE ENTOMOLOGIST. 



and second siibraarginal is incomplete, and in the last- 

 named cell, which is of a rather dark smoke-colour, is a 

 brown horny spot. 



Gn the 12th or 13th of September, J 862, 1 observed a 

 female sawfly, answering the above description, depositing 

 her eggs in a leaf-stalk of a birch tree in my garden, at 

 Leyden ; the eggs were inserted into either side of the 

 petiole ; one side is represented at fig. 2. The leaf-stalk 

 appeared to be enlarged or swollen at the spot where the egg 

 was concealed beneath the epidermis. As before remarked, 

 this was in the middle of September; I must thus conclude 

 that this was the second generation, as in the following year 

 I found full-grown larvae in the middle of the month of 

 August. T also observed that the eggs of this first generation 

 were laid in the petiole of a May leaf, which leaf was eaten 

 out by the young larva?, so as to have the appearance of 

 having been riddled by small shot, while the little creatures 

 had afterwards gone to feed in company on the leaves of the 

 branch growing immediately above the leaf which had been 

 consumed. I sometimes counted fourteen eggs in the two 

 rows. What surprised me was that the young larvae con- 

 sumed the oldest leaf first, then a somewhat younger leaf, 

 and so on, always proceeding to younger leaves. As before 

 mentioned, the eggs deposited in September on the birch 

 tree in my garden were enclosed in the petiole. I had 

 captured the sawfly which laid these eggs, and was thus sure 

 of the species. 1 frequently inspected the eggs. On the 21st 

 of September I found two little larvae had made their 

 appearance ; judging from their size (fig. 3 a) they were at 

 least one day old, perhaps two : each had eaten a pretty 

 large hole in the leaf between the nervures. I took one of 

 them home, and from it drew the fig. 1, magnified. They had 

 twenty legs ; the head was shining pale brown, with round 

 black spots, in which the eyes were placed. The 1st segment 

 of the abdomen was yellow ; the others pale green, with 

 black longitudinal marks, on which were minute wart-like 

 tubercles, each serving as base to an extremely fine hair. 



Two days afterwards the one 1 had left on the tree had 

 disapj)eared, either having fallen or been picked off by a 

 bird. The one I had taken home increased but little in size, 

 and at the end of three or four days died. The following day 



