66 UNIVERSITY OF COLORADO STUDIES 



feet; James Peak Lake, 11,090 feet; Corona Lake, 11,185 ^ eet ; 

 Emerald Lake, 11,200 feet; Pumphouse Lake, 11,300 feet; Reynolds' 

 Lake, 11,300 feet; Stewart Lake, 11,305 feet; Ohmond Lake, 11,600 

 feet; Second Chicago Lake, 11,700 feet; Ice Lake, 12,188 feet; 

 Summit Lake, 12,740 feet. 



Collections were also made near the snowsheds at Corona, 11,660 

 feet, on James Peak, 12,500 feet and above Summit Lake, on the 

 north side of Mt. Evans, at 13,000 feet. This latter elevation is 

 probably the highest altitude at which protozoa have been recorded 

 in North America. 



Two lakes, Silver and Eldora, on which boats were available, were 

 sounded and dredged. Contrary to local belief, the lakes are very 

 shallow. Eldora Lake was found to be less than forty feet in depth, 

 and Silver Lake at its present height is about fifty feet deep. 



These mountain lakes of Colorado are evidently very old. Pro- 

 fessor Henderson, of the University of Colorado, speaking with refer- 

 ence to the above list of lakes, says that all the lakes he has seen above 

 9,000 feet are glacial. 



Protozoa were found at the bottom of the lakes dredged, but these 

 lakes are too shallow to possess a peculiar fauna such as Penard found 

 in the very deep lakes of Switzerland. 



Temperature records of all the lakes mentioned above have prob- 

 ably not been taken. Dr. G. S. Dodds, in 1908, 1 took a number of 

 readings, and has kindly furnished the following: Long Lake, 

 August 20, 43 degrees; Yankee Doodle Lake, August 28, 53 degrees; 

 Corona Lake, August 28, 52 degrees; Pumphouse Lake, August 28, 

 53 degrees; Teller Lake, August 31, 55 degrees; Redrock Lake, 

 August 18, 62 degrees. The writer recorded the temperature of the 

 following lakes during 1911: Eldora Lake, August n, 58 degrees; 

 Pumphouse Lake, August 12, 41 degrees; Silver Lake, August 14, 52 

 degrees. Although the temperature of the lakes no doubt varies 

 considerably, the above readings may be considered as average tem- 

 peratures during the summer. Ice Lake, at the base of James Peak, 

 is very cold, snow and ice being found at its edge throughout the 



■ At that time an instructor in biology at the University of Colorado. 



