20- 



15- 



c 

 O 



E 



Z 



}0 



5- 



'Diptera 











-^ 



21 27 35 43 48 54 59 64 68 74 82 84 96 99 l03 107 11 



Sample Sites 



Figure 12. Number of qenera of the three major orders of anuatic invertebrates 

 found at each sampling site on Beaver Creek, 1977. 



-45- 



