PHYLUM PROTOZOA 



45 



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

 as many as thirty-two young flagellated Euglence 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 1. 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), Volvox (Fig. 27). 



Mastigameba (Fig. 24) is 



of special interest, since it 



Fig. 24. — Mas- 

 tigameba reptans, a 

 Flagellate. 



nu 



Fig. 25. — Chilo- 

 monas, a Flagellate. 

 c.v, contractile vacu- 

 ole; fl, flagella; g, gul- 

 let ; nu, nucleus ; x, 

 dorsal or upper lip ; 

 y, ventral or lower lip. 

 (From Jennings.) 



Fig. 26. — Uroglena ameri- 

 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 



