350 OHIO BIOLOGICAL SURVEY 



Trout are killed by an application of 1.2 pounds, while sunfish and 

 black bass can withstand 10-17 pounds. Euglena and probably 

 most other forms of the order are killed by the use of 0.4 pounds 

 to a million gallons of water. 



The method employed is that of taking ordinary commercial 

 crystals of blue vitriol to the required amount, placing in a coarse 

 bag and drawing through the water at the stern of a row boat 

 in parallel paths approximately twenty feet apart until the chem- 

 ical is dissolved. 



The various technical details in connection with the calcula- 

 tion of the volume of the water, the influence of the temperature 

 of the water on the solubility of the crystals, the amount of organic 

 material in the water as well as the specific kinds of organisms 

 present, render it advisable to consult some one familiar with the 

 process before undertaking purification by the copper sulphate 

 method. 



(b) NOTES ON ORGANISMS IN OHIO WATER SUPPLIES. 



A considerable number of water supplies in the state were ex- 

 amined and samples taken from receiving and storage reservoirs. 

 Among the cities visited were Cincinnati, Columbus, Cleveland, 

 Akron, Dayton, Cuyahoga Falls, Canton, Hamilton, etc. While 

 representatives of the Euglenoidina were not found in every in- 

 stance, a result to be expected inasmuch as the group is a re- 

 stricted one as compared with the numerous other groups of 

 unicellular and multicellular organisms occurring in fresh water, 

 many species of much interest were noted. Among these may be 

 mentioned Leptocinclis acicularis from the Cincinnati water sup- 

 ply, previously known only from Hungary in Europe ; Trachelo- 

 monas teres, known before only from New Zealand (Cincinnati 

 water supply) ; Notosolenus apocamptus and Entosiphov ovatum, 

 from the Hamilton storage reservoir; Trachelomonas rugulosa 

 and an undescribed species of Euglerm from the Storage Dam at 

 Columbus; Trachelomonas volvocina from Cuyahoga Falls, etc. 



While it is somewhat beyond the scope of the present paper, 

 certain other fresh water organisms found in the reservoirs may 

 be mentioned. 



In the large storage reservoirs at Cincinnati were noted Pofa- 

 mogeton spirillum and Potamogeton pectinatics, comparatively 



