128 



John F. Pagels, Leonard A. Smock and Stephen H. Sklarew 



Fig. 3. Frequency distribution (mean ± SE) of riffle, pool, and glide areas and 

 sediment particle sizes in four streams at which S. palustris was found in Vir- 

 ginia. BED = bedrock, BLD = boulder, COB = cobble, PEB = pebble, GRV = 

 gravel, SND = sand. 



100 



C^ 75 



50 



O 



z 



LU 



Z) 



o 



LU 



8: 25 



a. Geomorphology 



VA V^F/A 



RIFFLE POOL GLIDE 



50 



40 



> 

 o 



30 



2 





LU 





3 





O 



20 



LU 





tt 





10 



b. Sediment Particle Size 



v-fcn. 



BED BLD COB PEB GRV SND 

 SEDIMENT TYPE 



