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



Difflugia pyriformis Perty. 



This species was taken late in January in floating Spirogyra 

 from Station C, in which it was abundant. It had become 

 plentiful about this time in a culture containing dead Oedogo?iium 

 taken at Station H which had been standing four months. 



Length 40-208m. 



Difflugia corona Wallich. 



One individual was taken late in October in floating Spiro- 

 gyra (Station C). The animal occurred abundantly late in 

 January on the sediment at Station F, which is very close to 

 the preceding station. All were very active and had a pair of 

 widely divergent spines on the fundus. 



Diameter of the shell 128-176/i; length of spines 48ju.. 



Centropyxis aculeata (Ehrenberg). 



This form was not recorded from fresh collections, but was 

 found abundantly in material from three different stations, 

 that had been standing in the laboratory for two months. 

 This material consisted of alga-covered poplar roots from Station 

 D, algae from spring water at Station E, and sediment drained 

 from leaves in the smaller pond (Station A). Some of the shells 

 w^ere made up mostly of sand grains; and in others, the chitinoid 

 shell was impregnated with only a few grains of sand. Three, 

 six or seven spines were present on the fundus. 



Length 112-117^. 



Lecquereusia modesta Rhumbler. 



One individual was taken in March among algae scraped 

 from a submerged stone at Station G. The shell was impreg- 

 nated with a large number of sand grains. 



Length of shell 112jLt; breadth 90ju. 



Euglypha brachiata Leidy. 



This species was common among alga-covered poplar roots 

 (Station D) from November to the end of January. 



Length 80-88/x; breadth 32^. 



Euglypha ciliata (Ehrenberg). 



One individual was taken from Station G, where algae were 

 scraped from a submerged stone. The collection was made 

 late in January. 



Length 64/x. 



