ECOLOGICAL STUDY OF DRY RUN 



123 



are 27 shows how well hshcrnien are rewarded with crayfish after 

 making a single haul of the seine. 



Undoubtedly a study of the aquatic insects and smaller aquatic 

 organisms will shed further light on the reason why Bolcosoma and 



Fig. 26. — Water from one of the large springs just before it enters Cedar 

 River. 



Pig. 27. — Fisliermen collecting cruyflsli in one of the pools left just above the 

 uppermost quarry. This pool vanishes in dry weather. 



Notropis are restricted in their distribution. Certainly, the fact 

 that they are confined to or near regions possessing a gravelly bot- 

 tom would indicate that this has something to do with their dis- 

 tribution. The abundance of fish at the headwaters would indicate 

 that there is an abundance of fish food there and would indicate 



