408 OHIO BIOLOGICAL SURVEY 



El Pharyngeal siphon absent. 



Pi Posterioi* flagellum twice the 

 length of the anterior flag- 

 ellum. 



G^ Keel like ribs absent . 9. Gen. Anisonema 

 G- Keel like ribs present. 10. Gen. Ploeotia 

 F- Posterior flagellum approxi- 

 mately equal in length to the 

 anterior flagellum. 

 Gi Without an apparent 

 ventral longitudinal fur- 

 row; metabolic . 11. Gen. Metanema 

 G- Without an apparent 

 . • longitudinal furrow; not 



metabolic . . 12. Gen. Marsupiogaster 



E- Pharyngeal siphon present . 13. Gen. Entosiphon 

 C- (Subfam. Clautr'avieae) A single flagellum 



directed posteriorly ... 14. Gen. Clautriavia 



B- (Subfam. Divevieae) Granules arranged spirally 



in the ectoplasm; species 75-80m. in length. 15. Gen. Dinema 



1. Gen. EUGLENOPSIS Klebs. 



Form spindle shaped, colorless or yellowish white, slightly 

 metabolic, free swimming with rotation on axis ; a single flagel- 

 lum ; pellicula more or less spirally striate ; an anterior mouth- 

 like fold present. 



Habitat, fresh water. 



Distribution, cosmopolitan ( ?) . 



The genus consists of a single species. 



1. E. vorax Klebs (Fig. 1, PI. XXIII). 



Possessing the characters of the genus with protoplasm color- 

 less and containing numerous paramylon granules. 



L. 20-25/x. D. 8/1. 



Distribution, cosmopolitan. 



While its small size will aid in distinguishing it from many 

 other species belonging to the family Astasiidae, some of which it 

 resembles, the possession of the mouth-like fold is the character 

 of importance. Thus far it has not been noted from Ohio. 



2. Gen. PETALOMONAS Stein. 



Cells rigid, not metabolic ; unsymmetrical in form and often 

 with peculiarly developed processes; periplast thick and firm and 



