Biological Survey — Erie-Niagara Watershed 139 



Indicators Tolerant of Sewage Pollution as Found in the 

 Erie=Niagara Watershed 



Blue-Green Alo^ae. 

 Oscillatoria sp. 

 Phormiciium sp. 



Green Algae 



Sceneclesmus bijuga 

 Scenedesmns dimorphns 

 Scenedesmus aeutifonnis 

 Scenedesmns quadricauda 

 Scenedesmns abnndans 



Pediastrnm Boryannm 



Ankistrodesums sp. 



Diatoms 



Navicnla sp. 



Fungus 



Sphaerotilus sp. 



Large plants 



Potamogeton pectinatus 

 Potamogeton Richardsonii 

 Potamogeton natans 

 Potamogeton compressus 

 Potamogeton pusillus 

 Vallisneria americana 

 Najas flexilis 



Insects 



Eristalis tenax 

 Psychoda sp. 



Roundworms 



Tubifex tubifex 



Mollusca 



Planorbis trivolvis 

 Physa Sayi 

 Physa heterostropha 

 Phidium variable 



