412 OHIO BIOLOGICAL SURVEY 



10. P. quadrilineata Penard (Fig. 11, PI. XXIII). 



Fusiform, rounded posteriorly; flagellum 2 times length of 

 body. 



L. 12-15/x. D.(?). 

 Europe, Wiesbaden. 



11. P. sulcata Stokes (Fig. 12, PI. XXIII). 



Oval, less than twice as long as wide, truncate posteriorly, 

 dorsal and ventral surfaces each with 4-5 longitudinal or slightly 

 obhque carinae, which at times meet posteriorly; flagellum equal 

 to length of body. 



L. 3V D.(?). 



Distribution, North America. Ponds. 



12. P. alata Stokes (Fig. 13, PI. XXIII). 



Oval, broadly rounded posteriorly, with 4 extremely high 

 longitudinal carinae, height much greater than diameter of body, 

 in furrows between carinae; flagellum 2 times length of body. 



L. 23/x. D.(?). 



Distribution, North America. Ponds with Ceratophylliim. 



3. Gen. SCYTOMONAS Stein. 



Form oval, somewhat flattened; truncate anteriorly; not 

 metabolic ; flagellum arising from one side of anterior end ; vacuole 

 anterior, circular or triangular in outline; movement creeping as 

 in Petalomonas. 



Distribution, cosmopolitan. 



TABLE OF SPECIES. 



Ai Oval, narrowed anteriorly. 



B^ Frequenting digestive tract of fi'ogs and toads, also stag- 

 nant waterf?), nucleus posterior .... 1. S. pusilla 



B- Frequenting digestive trace of Molge vulgaris, — nucleus 



anterior . . . . . . . 2. S. dobellii 



A2 Elongately oval with broadly rounded ends, not distinctly nar- 

 rowed, anteriorly . . . . . . 3. S. major 



1. S. pusilla Stein (Fig. 14, PI. XXIII). 



Oval, distinctly narrowed anteriorly and rounded, or rarely 

 fusiform or emarginate; flagellum li/^ times length of body; 

 nucleus posterior, rarely central. 



