THE LIFE OF DEVILS LAKE 79 



newaukan Ba.y, Creel Bay and the main lake. Abundant in East 

 Lake." 



Spirostomum amhiguum. "Observed in dredged material from 

 Creel Bay." 



Steyitor sp. Reported by Moore (1917) from Main Lake. 



Halteria grandinella. Common and widely distributed in Main 

 Lake, both in ooze and infusions of Ruppia and algae. 



Uroleptus agilis. Occasional in ooze in ]\Iain Lake. 



Uroleptus rattulus. Occasional in Ruppia in Main Lake. 



Oxytricha. This genus is probably the most characteristic 

 genus in the lake, both in respect to variety of species and number 

 of individuals, almost every infusion of Ruppia containing them. 

 Four species have been determined, but it is Professor Edmondson's 

 opinion, that further study would reveal others. These four are 

 fallax, pellionella, parvistyla, and bifaria, of which pellionella ia 

 the commonest. The latter is reported from Lake A also. The 

 others from Main Lake onl}-. Bifaria? has been seen with con- 

 tained diatoms (Navicula?). 



Histrio erythysticus. In Ruppia in Creel Bay. 



Stylonichia notophora. "With algae from Creel Bay." 



Holosticha vernaUs. "Among Ruppia from the main lake." 



Pleurotricha lanceolata. "Taken at the head of Creel Bay." 



T achy soma parvistyla. "Observed in infusions from Stump 

 Lake only." 



Euplotes charon. This species and E. patella are among the 

 most abundant Protozoa in the lake. Charon is reported from East 

 Lake also, while patella occurs in Stump, East Lake and Lake A. 



Aspidisca costata. Abundant in Ruppia infusions thruout the 

 main lake. 



The genera Vorticella and Cothurnia are the only Protozoa 

 which occur with any frequency in the plancton. This may be due 

 to the fact that they are carried out of their natural habitat in 

 the Ruppia by animals or plants to which they are attached. No 

 attempt at specific determination has been made in the plancton 

 counts. Vorticella occurs frequently at all seasons while Cothurnia 

 appears more rarely, but it is probably perennial also. My records 

 run from June 22* to December 30. 



Six species of Vorticella, two of them indeterminate, have been 

 observed by Professor Edmondson as follows : telescopica, convallaria, 

 octavo, microstoma and two sp. Of these convallaria is reported from 

 Lake A. also. 



Gerda annulata. "Among algae and Ruppia from the north 

 end of the main lake." 



EpistyUs plicatilis. "From . . . Creel Bay." 



•June 21 in East Lake. 



