1881] 251 



the leaf, it did not go on from the very end of the cut already made, 

 but began again at a point a little distance further back, thus finally 

 bringing out the channel with a shorter rounder curve, which had the 

 effect of making the detached piece of leaf more symmetrical in 

 outline. It was now afloat, with its ventral and anal legs clinging to 

 its raft, but very soon it applied its thoracic legs to the fixed part of 

 the leaf, and, guiding its course by them, conveyed itself and its raft 

 under the leaf, apparently looking for a suitable place, whence to cut 

 the other half of its case ; presently it seemed to find what was 

 wanted, the floating piece was made fast, and after some hours the 

 upper half was cut out and detached, and the larva floated in its finished 

 dwelling. Continuing to watch it, the next thing I noticed was a rapid 

 horizontal motion of the head and front part of the body of the larva, 

 just within the case from one side to the other ; then turning about, 

 after a pause, the larva repeated this movement at the other end, rested 

 awhile, and again repeated the movement : next it turned round again x 

 and protruded its head from the former end of the case, with the air 

 of taking a survey of the outside, and whilst it was in this position a 

 small silvery air-bubble floated out from inside the case, and when the 

 larva, turning round once more, put out its head from the other end 

 as if surveying that also, the bubble seemed somehow to be attracted 

 and moved over and settled close to its head : after this, the larva set 

 about feeding, and journeying for about an inch, reached the stem of 

 the plant and fed on it for some time, and then moored its case to the 

 stem by a thread and rested : afterwards I saw it eating patches of 

 leaf-cuticle, soon effecting a large hole through the entire substance ; 

 next day I saw it again eating, and noticed that from time to time it 

 stopped this occupation, withdrew its head into its case, and made from 

 five to thirteen of these rapid movements from side to side ; vigorous and 

 rapid as these movements were, they did not shake the case, and I think 

 were quite independent of it ; indeed, I am disposed to regard them 

 as in someway connected with the act of respiration, being analogous 

 to the movements of the larva of Paraponyoc stratiotalis, described by 

 me at p. 161, vol. xii, of this Magazine. Bearing on this point also 

 will come some observations I made on the presence of water ivithin 

 the case ; once or twice it happened that a larva had brought its case 

 into such a position that a good portion of it was above the surface of 

 the water, and I was able to look down the opening at the end into 

 the interior, quite through to the other end, and I made sure that it 

 was full of water, and once I could notice a small silvery air-bubble 

 clinging to the side of the case : probably, when the larva fastens up 



