THE EUGLENOIDINA OF OHIO 387 



G- Collar absent. . . 14 T. lemmermannii 



E- Form ovoid, being broader either an- 

 teriorly or posteriorly. 

 Fi Broadest posteriorly. 



Gi Shell smooth. . . 15. T. ovalis 



G- Shell covered with punctua- 

 tions or granulations. 

 H^ Covered with fine irregu- 

 lar punctuations. . 16. T. similis 

 H- Covered with coarse reg- 

 ular granulations. . 17. T, volzii 

 F- Broadest anteriorly. 

 Gi Shell smooth. 



HI Collar absent or low. 

 I^ Flagellum opening 

 with a notched col- 

 lar. . . 18. T. eurystoma 

 I- Flagellum opening 

 only slightly thick- 

 ened. . . 19. T. incerta 

 H- Collar comparatively 



high. . . . 20. T. africana 

 ° G- Shell covered with fine punc- 



tuations and lines. , 21. T. reticulata 

 D- Form cylindrical. 



El Shell smooth 22. T. euchlora 



E2 Shell with coarse granulations. . 23. T. conspersa 

 B2 Posterior end of shell produced into a spine-like 

 process. 



Ci Shell either with 3 annular transverse furrows 

 or with elongated collar the height of which 

 approximates the diameter of the shell. 



Di "With 3 annular furrows. ... 24. T. annulata 

 B- With elongated collar. ... 25. T. minor 



C- Shell without transverse furrows and elon- 

 gated collar. 



Di Anterior end of shell obliquely truncate. 

 E- Form oval. 



Fi Elongately oval. ... 26. T. affinis 

 F- Transversely oval. . . 27. T. volgensis 



El Form triangular or trapezoidal. . 28. T. acuminata 

 D- Anterior end transversely truncate. 



E' Posterior spike-like process not longer 

 than diameter of shell. 



Fi Median part of shell cylindrical. 29. T. urceolata 

 F- Median part of shell oval. 



G' Median part longitudinally 



oval. . . . 30. T. fluviatilis 



