406 OHIO BIOLOGICAL SURVEY 



about as long as body ; nucleus posterior or central ; paramylon ( ?) . 

 L. 16-25|.. D. 7-8/.. 

 Distribution, Europe. Stagnant water. 



3. Gen. DISTIGMA Ehrenberg. 



Decidedly metabolic, elongately fusiform ; periplast weakly 

 striate longitudinally ; movement free-swimming or creeping ; re- 

 production by division of motile forms, cysts being unknown. 



A single species. 



1. D. proteus Ehrenb. (Fig. 14, PI. XXII). 



Elongately fusiform ; primary flagellum Yo length of body ; 

 secondary flagellum short ; paramylon granules cylindrical. 

 L. 46-110/1. D.(?). 

 Distribution, cosmopolitan ( ?) . 



4. Gen. SPHENOMONAS Stein. 



Rigid, with longitudinal keels ; periplast longitudinally striate, 

 with a primary and secondary flagellum ; reproduction by division 

 during motile condition. 



TABLE OF SPECIES. 



Ai 1 longitudinal carina present . . . . 1. S. teres 



A- 4 longitudinal carinae present . . . . 2. S. quadrangularis 



1. S. teres (Stein) (Fig. 15, PI. XXII). 



Broadly fusiform ; longitudinal carina weakly developed ; pri- 

 mary flagellum as long as or slightly longer than the length of the 

 body ; secondary flagellum short ; nucleus anterior. 



L. 20-40/1. D. 8//,. 



Distribution, cosmopolitan ( ?). Stagnant water. 



2. S. quadrangularis Stein (Fig. 6, PI. XXII). 



Broadly fusiform, quadrate in cross-section, with 4 well de- 

 veloped carinae; primary flagellum 2 times length of body; sec- 

 ondary flagellum short; nucleus central. 



L. 30/1. D. ( ?) . 



Distribution, Europe. Stagnant water. 



3. Fam. PERANEMIDAE Ehrenberg. 



Colorless, green chromatophores and red stigma being absent; 

 form bilateral as a rule, movement usually creeping although a 



