Fig. ii6. Salmon colored ?tone-riies [ Ptcronarcys 

 calif ornica) " emerging " from the larval skins. In 

 the upper specimen the larval skin has just split; in 

 the lower one the head and legs are free. Photo Juh- 25. 



Fig. 117. Stone-flies '" emerging " on a rock near Yellow- 

 stone River Bridge. Some of the dried cast larval 

 skins are sticking to the rock. Photo Tulv 6. 



