FLAGELLATE PROTOZOA (MASTIGOPHORA) 



263 



156 (iSS) Forming annular colonies; individuals closely united. Flagella 



two, unequal Cyclonexis Stokes. 



Representative species. . . . Cyclonexis annularis Stokes 1886. 



From ten to twenty zooids, not in contact in older colonies, leav- 

 ing a central, circular space. Zooids obovate, about twice as long 

 as broad. Length of zooid 10 to 15 11. Marsh water. 



Fig. 434. Cyclonexis annularis. X 625. (After Conn.) 



157 (138) Withalorica 158 



158 (163) Not forming colonies 159 



159 (162) Lorica sessile 160 



160 (161) Lorica beaker-shaped; usually with a peristome process. 



Epipyxis Ehrenberg. 

 Representative species. . Epipyxis utriculus Ehrenberg 1838. 



Lorica is truncate or slightly everted anteriorly, widest centrally and pointed 

 posteriorly. Body occupies about one-half the cavity of the lorica, and is at- 

 tached by a thread-Hke pedicel to one side of the lorica. An eye-spot usually 

 present. Nucleus central; contractile vacuole anterior. 



Length of lorica about 40 ju. Attached to water-plants. 



Fig, 435. Epipyxis utriculus, X 650. (After Stein.) 



161 (160) Lorica urn-shaped. . . 

 Representative species. 



Chrysopyxis Stein. 



Chry so pyxis urceolata Stokes 1886. 



Zooid occupying the center of the lorica, but in no way attached to it. 

 Flagella two, long, diverging. Yellow chromatophores often present. Nu- 

 cleus centrally located; contractile vacuole posterior. Length of lorica 12 /i. 

 Attached to algae. 



Fig. 436. Chrysopyxis urceolata. X 1200. (After Stakes.) 



