8 



COMPARATIVE ANATOMY 



CHAP. 



serving for locomotion, and often also for capturing food. With contractile vacuoles. 

 Multiplication by fission, or formation of spores, or gemmation, often after previous 

 copulation of the reproducing individuals. 



Order 1. Flagellata s. str. 



During active life armed exclusively with flagella (without collar or cilia). Monas, 

 Euglena, Chilomonas (Fig. 9), Uudorina, Pandorina, Stephanosphcera, Volwx (Fig. 

 21, p. 21). 



1 



FIG. 9. Chilomonas Paramaecium, 

 after Biitschli. s, Oral aperture ; cv, con- 

 tractile vacuole ; n, nucleus. 



FIG. 10. Protospongia Haeckelii, after Kent. 



Order 2. Choanaflagellata. 



Flagella at their basal portion surrounded by a funnel-shaped collar. Phalan- 

 sterium, Salpingoeca, Protospongia (Fig. 10). 



Order 3. Cystoflagellata. 



The protoplasm shows a reticulated structure similar to that of vegetable cells. 

 Noctiluca (Fig. 11), Leptodiscus. 



Order 4. Dinoflagellata (Cilioflagellata). 



Shelled forms ; besides the freely projecting flagellum there is a second, peculiarly 

 placed, in a special groove running across the body, giving the appearance of vibrat- 

 ing cilia which deceived earlier observers. Peridinium, Ceratium (Fig. 12). 



CLASS IV. Gregarina. 



Parasitic Protozoa of elongated form. Invariably one nucleus. Without pseudo- 

 podia, without cilia, without contractile vacuoles, without special differentiation of 

 the protoplasm, with outer cell integument. Multiplication by spore-formation, with 

 previous copulation or conjugation. 



