PLATE XXXVIII. 



Fig. 1. Typical breeding place of Simulmni vittatum, Turkey creek, 

 Oswego, Kan. 



Fig. 2. Pups on the under side of a stone, from ripples in the stream 

 shown in figure 1. (Slightly reduced.) 



Fig. 3. A Sivmlium fly trap in a ripple, showing the method of catch- 

 ing the flies as they emerge. When removing the flies from the trap a 

 black cloth is put around the white cone over which Prof. S. J. Hunter 

 is holding a glass bottle for the flies to emerge into. 



