136 THE AMERICAN MIDLAND NATURALIST 



would shade the rays of the sun these forms would come nearer to 

 the surface and with the passing of the cloud the forms would 

 descend. 



At Stations VII, VIII, and IX, which were at the outlet of 

 the Cove all the forms fluctuated owing to the wind currents 

 producing waves. Especially was this true when the wind came 

 from the south or the southeast. On calm days the greater numbers 

 were found near the surface while on windy days they were entirely 

 absent or only a few near the bottom. Very seldom was the nauplius 

 stage found at this station. 



- At Stations I, II, VII, and IX, the water was shallow and the 

 temperature remained constant or would tend to constancy through- 

 out the slight depth, depending upon atmospheric changes. At 

 these stations the forms were found to be numerous on warm, 

 bright days but very few could be found on cool, dark days; at 

 such times they were more numerous in deeper water where less 

 fluctuations in temperature occurred. Greater fluctuations occurred 

 in the narrow Cove which was also shallower, than in Lake Erie 

 or in the abandoned quarry pond to be described later, both of 

 which were considerably deeper. 



This sums up only a very minute portion of such a vast problem 

 and only a few conclusions have been drawn. In addition the 

 following data was collected on trips taken to neighboring bodies 

 of water and also on some other observations made in Beimiller's 

 Cove. 



Blue Hole, Castalia. 



Blue Hole is located at Castalia, Ohio, which is about six 

 miles southwest from Sandusky, Ohio, close to the Big Four 

 R. R. tracks. 



A party of four made observations and collected material 

 from Blue Hole, July 3rd, 1916. We arrived at this place at 10:45 

 a. m., the weather conditions being ideal. The sky was clear, the 

 sun hot and the wind very perceptible. 



The Hole is 80 feet long, 64 wide and about 45 deep; having 

 two small outlets about 3 feet wide, leading from either side. It is 

 surrounded by a narrow path about 2 feet wide and surrounding 

 this there is thick vegetation, 6 inches to 3 feet high. . Extending 

 from the bank, out about 2 feet on the top of the water there is a 

 shelf of plant life made up of moss, chara, algae, spirogyrae, and 

 other forms intermingling. 



