Explanation of Plate Z- 



^pbemera varia Etn. 



1. Lateral view of the nymph. Note the latero-dorsal breathing organs or gills on 



the abdominal segments. 



2. Dorsal view of the nymph. This view shows how these organs may arch over 



the back. 



3. Lateral view of the male imago. 



4. Dorsal view of the male imago. 



3ipf)tQrQs alternatus Say. 



5. Lateral view of the nymph. This larva possesses a different type of abdominal 



breathing organs or gills. 



6. Dorsal view of the nymph. This view shows the overlapping of the gills and 



also gives some hint of the number of tracheae or air tubes, represented by 

 black lines in each. 



7. Lateral view of the male imago. 



508 



