106 The Ohio Journal of Science [Vol. XX, No. 4, 



Order Euglenida. 

 Family EuglenidcB. 



Euglena acus Ehrenberg. 



This form was found in a culture of algae taken from a 

 submerged stone (Station G) in the early part of December. 

 The culture had been left standing in the laboratory for nearly 

 two months. 



Length 80-144^; breadth IOm- 



Euglena acus Ehrenberg, variety rigida Hiibner. 



One individual was taken in sediment from Station B in 

 late November. It was characterized by the spiral arrangement 

 of the rod-shaped paramylum grains and the greater rigidity 

 of the cell. There were twelve paramylum grains in the 

 specimen taken. 



Length 120iu; breadth ll^u. 



Euglena deses Ehrenberg. 



During October and November, this form was taken 

 occasionally amqng floating Spirogyra (Station C) and in 

 sediment from Station F. During the two months that ice 

 covered Mirror Lake, the species was not taken. Late in 

 February and throughout March, it was common in algae from 

 Station H and from submerged posts (Stations I and I'). 



Length 112-116^; breadth 12-19^. 



Euglena gracilis Klebs. 



This form was common in one collection of algae growing 

 on poplar roots (Station D) taken in January. The organisms 

 showed a peculiar kind of metabolic movement; the posterior 

 end of the cell was ver}^ active while the anterior half remained 

 motionless. 



Length 40-46ju. 



Euglena granulata (Klebs). 



This species was exceedingly abundant in a two months old 

 culture of algae taken from a submerged stone (Station G) early 

 in December. 



Length 80-88m; breadth 24^. 



