88 THE ENTOMOLOGIST. 



ten days, and they did make what resistance they were capable 

 of, by throwing themselves violently to and fro from side to side 

 during the process of investigation by the ichneumons' antennae 

 and subsequent parasitization, and would often fall to the ground 

 with the parasite attached, but it was all wholly ineffectual. 



On an average about four larvae were parasitized a day, but 

 very likely more would have been had they been supplied, and 

 no doubt it falls short of the number had the insects been at 

 large. 



From one cause or another I lost all my Emphytus larvae in 

 which ova had been deposited except one, parasitized on the day 

 of the first ichneumon's capture. For some time prior to July 

 27th this larva had been lying quiescent as though dead, 

 which no doubt it was, as on that day the parasitic larva 

 emerged from it, leaving only the shrivelled skin, showing that 

 it had occupied the whole of it. Ordinarily, no doubt, the 

 sawfly larva would have entered a stem of some sort, containing 

 pith, as is their habit, with the intention of pupating, but 

 nothing of this nature was provided. 



The M. palustris larva was cylindrical, the head and first 

 segment and the two apical segments quite white, the inter- 

 vening space being green from the interior parts of the creature 

 showing through the skin. There was a very dark green line, 

 bordered by white granules along the dorsal area, throughout the 

 length of the green part, the lateral lines, ventro-lateral lines 

 showing only in the segmental divisions, and a dark ventral 

 line. I counted fourteen segments, including the cephalic one. 

 There was a very slightly discreted border, not very evident. 

 The mouth parts were discreted with fuscous and the autennal 

 tubercles, large, concolorous, and not protruding beyond the 

 level of the head. 



The animal had begun to spin some strands of silk, evidently 

 the commencement of its cocoon, presuming this to be a cocoon- 

 spinning species, which it had every indication of being. But 

 I removed it to figure the facial characters, and have found 

 that to do this with larvae of other species disorganizes them to 

 the extent of incapacity to ever finish the cocoon, as was the 

 case with this one, but it did not result in its ultimate demise as 

 I expected. 



It was now placed in a glass tube, where it spun some silk 

 at each end. 



On August 1st signs of pupation began to show, a red spot 

 appearing on each side under the skin of the second body- 

 segment, the eyes of the imago forming, the next three segments 

 showing the contraction for the thorax, now turned to yellowish, 

 the rest white and taking on more of the future imaginal abdo- 

 minal outline, the extreme apex being buried in a thick black 

 fluid, the larval excreta. 



