100 [October, 



f inch in length : after being turned out of its tenement into the 

 water, it seemed not the least incommoded, but without once approach- 

 ing the surface, or causing any air-bubble, it walked about on the 

 saucer at the bottom of the water, raising its head and extending it as 

 though searching for the Sparganium ; and when two or three small 

 fragments were given to it, soon connected them together with silk 

 threads ; presently, however, not finding them sufficient, it grew dis- 

 contented and wandered about until it was restored to the growing 

 plants, when it at once crept between two floating leaves, and made itself 

 snug again in a new habitation. After this, at intervals I disturbed one 

 or two more, and was unlucky enough to find them waiting for a moult. 

 On May 21st, while again removing Conferva, I found two larvae less 

 advanced than the others, of rather an olive tint, and both laid up 

 for moulting. 



The first moth appeared on the evening of June 29th, and the 

 second on the 6th August, — during the interval, my stock had been 

 diminishing from the attacks of a merciless dragon-fly larva, of which 

 once or twice I had a momentary glance, but which I failed to secure 

 until almost too late, for then only two pupae remained, the last of 

 which I sacrificed to the necessity of figuring and describing, and the 

 other produced the second moth. 



This sketch of the progress of stagnnlis reared from eggs on 

 Sparganium simplex will have shown that on this plant the larva is a 

 veritable miner from the moment it leaves the egg-shell until after 

 hibernation in the spring, when it finds itself unable to mine into the 

 young leaves of its food-plant, which are then too narrow and thin for 

 the purpose, but, accommodating itself to the changed condition of 

 the plant, it now spins parts of the flaccid leaves together and lives 

 between them, securely hidden from view. 



Its habits on Sparganium ramosum, a plant of larger size, are some- 

 what different : this plant in spring at first bends under any flowing 

 water, but soon gathering substance and strength stands erect, and 

 the larva, after hibernation, is still a miner, no longer indeed eating its 

 way longitudinally through the tissues of a single leaf, but excavating 

 large irregular perforations through some of the inner leaves, generally 

 sparing the keel as well as the fibre at the outer margins, so that, when 

 thus ravaged, the leaves can still retain their position. 



The larva keeps itself a little below the surface of the water, and 

 as the plant grows, the ravages in the leaves turn blackish, and become 

 exposed to view at a distance above it, and thus afford a sure indi- 

 cation of the larva below, generally about where the green colouring 



