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towards each end rather suddenly ; the head rather small ; the segmciits decreasing 

 in thickness from the seventh, and again decreasing from the tenth to the anal tip, 

 all well defined by deep, yet close, divisions ; the tliird and fourth segments with 

 three sub-dividing wrinkles on the back, the other segments with only one deep 

 wrinkle, the sides dimpled ; the anterior legs tolerably well developed, the ventral 

 and anal legs mere fleshy swellings with a flat process at the extremity fringed with 

 fine hooks. The colour of the head light olive-brown, the lobes and mouth darker 

 brown ; a pale olive shining plate on the second segment margined both in front and 

 behind by a fine black line, and within it, after an interspace ef the pale ground, 

 there is, in the middle, a transverse fusiform brownish-black mark dorsally divided 

 by a thin pale line ; the rest of the body above light olive brown with a darker 

 dorsal stripe, and fainter indications of a sub-dorsal stripe less dark ; the body beneath 

 much paler, of a light buff colour very faintly tinged with olive ; no abrupt 

 change of colour to mark the division of the back from the belly, as the tints of both 

 melt slightly together along the spiracles, which are very small, roundish oval, 

 level with the skin, of the ground colour delicately outlined with reddish-brown ; 

 the hooks of the feet dark brown ; the whole skin soft and velvety, appearing darker 

 in the depths of the segmental divisions, and paler at the folds. 



After remaining quiet about ten minutes, wliilst I was making my observations, 

 the larva began by degrees to recover from its fright, and, regaining confidence, 

 turned back into the water, sinking in it to the bottom, about an inch in depth ; 

 here it stretched itself out to the length of apparently an inch and a half,* looking 

 very thin and silvery, reminding me of a preserved larva unnaturally attenuated ; in 

 this way, by its motions, it appeared to be searching for its case, or for the food- 

 plant ; and when presently its empty case was placed on the water near it, and it 

 contrived to touch the case with its head, it seemed baflled at first in its attempts to 

 get into it, but in a few minutes, while struggling with the buoyant structure, it 

 arrived with it at tlie side of the saucer, up which it crawled, and from thence on to 

 the top of the case, appearing perfectly dry, and with its previous proportions and 

 shape resumed ; and, on coming to one end of the case, it tucked down its head, and 

 in a couple of seconds had entered within, and was out of sight. I then examined 

 the smaller larva, and found it varied only in being a little deeper coloured. After 

 tliis I left them quiet, and they seemed very shy for a couple of days, and lay under 

 the lowest broad leaf of the floating Potamogeton ; but while thus hidden themselves 

 from view, tlieir situation could be made out, easily cnougli, by the large discoloured 

 curved blotchea they caused on the leaf by eating away the lower cuticle, and 

 occasionally making a small hole quite through the upper surface ; this leaf was 

 nearly consumed by the fifth day, by which time their shyness had in a measure 

 worn off, and they were then eating at the edges of another leaf, their cases in view 

 alongside, or lying above the leaf : on the seventh day, I noticed the largest larva 

 had drawn the edge of a leaf a little way within the opening of its case, and was 

 then eating without at all exposing itself: its companion at this time was lying 

 hidden in its case at the bottom of the water for several liours, but it came up again 

 and fed at intervals, often protruding its front segments as it crawled along the stems 

 and leaves of the plant ; the largest larva also at times protruded as many as seven 

 segments downwards, as though exploring the depth of the water, but was generally 



* Probably an optical cfioct of water. 



