PHYLUM PROTOZOA 



45 



cyst wall, making four in all. Recent observers have recorded 

 as many as thirty-two young flagellated Euglena which escaped 

 from a single cyst. 



b. Mastigophora in General 



The MASTIGOPHORA may easily be distinguished from other 

 PROTOZOA by the presence of one or more flagella. Four orders 

 are usually recognized: (i) FLAGELLATA, (2) CHOANOFLAGEL- 



LATA, (3) DlNOFLAGELLATA, (4) CYSTOFLAGELLATA. 



Order i. Flagellata. -- MASTIGOPHORA with one or more 

 flagella at the anterior end of the body. Examples: Euglena 

 (Fig. 22), Mastigameba (Fig. 24), Chilomonas (Fig. 25), Uroglena 



(Fig. 26), Volwx (Fig. 27). 

 Mastigameba (Fig. 24) is 

 of special interest, since it 



-P 



FIG. 24. Mas- 

 tigameba re plans, a 

 FLAGELLATE. 



--nu 



FIG. 25. - - Chilo- 

 monas, a FLAGELLATE. 

 c.v, contractile vacu- 

 ole; ft, flagella; g, gul- 

 let ; nu, nucleus ; .v, 

 dorsal or upper lip ; 

 y, ventral or lower lip. 

 (From Jennings.) 



FIG. 26. Uroglena amcri- 

 cana, a large colonial FLAGEL- 

 LATE. (From Bergen and Davis, 

 adapted after Moore.) 



appears to combine the distinguishing characteristics of both 

 the RHIZOPODA and MASTIGOPHORA, that is, it possesses pseudo- 

 podia and also a distinct flageilum. It is therefore able to creep 

 about on a solid object or swim directly through the water. 



Chilomonas (Fig. 25) is a very common FLAGELLATE in labo- 

 ratory cultures. Uroglena (Fig. 26) forms spheroidal colonies 



