64 MR. F. BALFOUR BROWNE ON AQUATIC COLEOPTERA 
in each month, and also the number of species captured in 
each month, and the results are represented in the following 
charts : — 
Now from these charts we can learn two important things': 
First, we can learn the distribution of the species in the district 
from the table showing the number of species per collection, 
mcnOT 
