THE EUGLENOIDINA OF OHIO 409 



occasionally developing a longitudinal carina or a longitudinal fur- 

 row; 1 flagellum arising from a depression on the right of the 

 cytopharynx ; a primary and a secondary vacuole usually to right 

 of cytopharynx ; nucleus usually at left of cell. 



Reproduction by longitudinal division; cysts not known. 



Nourishment, saprobiotic. 



TABLE OF SPECIES. 



Ai Longitudinal carinae absent although longitudinal fur- 

 rows which may be mistaken for carinae may be 

 present. 



Bi Posterior end without peculiarly developed pro- 

 cesses. 



C^ Lateral margins not turned inward. 



Di Broadly oval .... 1. P. mediocanellata 



D- Elongately oval . . . . 2. P. angusta 



C- Lateral margins turned inward . . 3. P. inflexa 

 B- Posterior end with peculiarly developed processes. 

 Ci Posterior lateral processes 2 in number; cell 

 not gradually narrowed anteriorly — but 

 nearly cylindrical . . . . 4. P. sinuata 



C- Posterior processes 6 in number; cell grad- 

 ually narrowed anteriorly . . . 5. P. sexlobata 

 A2 Longitudinal carinae present. 

 Bi 1-3 longitudinal carinae. 

 Ci 1 longitudinal carina. 



Di Carina with a sharp edge . . 6. P. steinii 



D2 Carina rounded . . . . 7. P. carinata 



C- 2-3 longitudinal carinae. 



D^ Posterior end rounded or truncate . 8. P. abscissa 

 D- Posterior end deeply emarginate . 9. P. mira 

 B- 4-5 longitudinal carinae. 



C^ Carinae not extremely developed. 



D^ Fusiform, rounded posteriorly; L.12-15m. 10. P. quadrilineata 

 D- Oval, truncate posteriorly; L.34m. . 11. P. sulcata 

 C- Carinae extremely developed, their height ex- 

 ceeding ordinary diameter of body . 12. P. alata 



1. P. mediocanellata Stein (Fig. 2, PI. XXIII). 



Broadly oval, ventral and dorsal sides with furrows, that on 

 the dorsal side being narrow; flagellum as long as bodv. 

 L. 22-25/x. D.(?). 



Distribution, cosmopolitan. Pools containing much vegeta- 

 tion. 



