78 LIFE STORIES OF AUSTRALIAN INSECTS. 



tails which are fringed, and these are regarded as 

 special respiratory organs. 



The life of the larva is thought to be very long, 

 extending over years in some species. 



An interesting feature is a stage called the sub- 

 imago. When the last larval skin is shed thei'e 

 emerges a winged may-fly, but with dull, opaque 

 wings, with numerous minute hairs, and differing 

 from the true imago — hence it is called the sub- 

 imago. Later this enveloping coat is shed and 

 the imago emerges, which has beautiful transparent 

 wings. May-fly larvae can be found in pools and 

 running streams. On lifting stones in the bed of 

 shallow creeks the larvae can usually be found 

 in all stages of development up to the large nymphs 

 with prominent wing-pads. (Plate ii. Figs. 4 and 



5-) 



The lateral gills are very interesting as they move 

 with a motion suggestive of the movement of a 

 silken flag in a gentle breeze. 



On examining the gill with the aid of the micro- 

 scope it can be seen with the main tracheae pro- 

 longed to form a distinct fringe at the apex and 

 outer side. (Plate 11, Fig. 6.) 



A common species found in our creeks, is 

 Atalophlebia australasica. 



