CADDIS-FLIES. 99 



Dack which projected outwards like a spine, and 

 two lateral ones, much shorter. (Plate 13, Fig. 

 8a). There were a pair of suckers at the end of 

 the abdomen. These processes probably enable 

 the larva to maintain its position in the case and 

 by adpressing the projections, it could slip smooth- 

 ly within the case. 



There is a group of Caddis flies belonging to the 

 Family Hydroptidac These are minute caddis flies, 

 and the larva which we observed was practically 

 microscopic. The case was transparent and 



brownish fawn, and we watched the larva feeding 

 on water plants, such as delicate algse. 



An interesting note on water insects was given 

 by Mr. F. W. Carpenter, M.A., in "The Austral- 

 ian Naturalist." It describes an excursion to 

 Ileathcote in July. ''Many larvae were obtained by 

 diligent dredging of the water weeds, and these 

 were carefully examined alive in a shallow white 

 dish full of water. The larvae of the dragon fly 

 Austrolestes cingiilatiis were found in various stages 

 of development, and in some the budding wings 

 were clearly visible. The fine caudal gills of this 

 genus were pointed out. The whirligig beetle 

 Macrogyra, and the back swimmer Notonecta (a 

 bug), were both found on the weeds. 



"The abundant fauna was discovered on the 

 under surfaces of submerged flat rocks. The 



small conical cases of the caddis larva Helicopsyche, 

 were seen to be built of fine sand grains, whilst 

 the green transparent pupa of Hydropsyche was 

 found hidden amongst a little mound of pebbles 



