The Mastigophora 128 



Life-cycles often include palmella or amoeboid stages. Species such as 

 Ochromnnas granularis (66) may become amoeboid (Fig. 4. 3, C) without 

 losing the fiagella. Amoeboid and flagellate phases occur in Chrysamoeba 

 radians (66) and Myxochrysis paradoxa (203); in the latter (Fig. 4. 6, 

 A-C), the amoeboid stage develops into a large plasmodium. A palmella is 

 dominant in life-cycles of the Chrysocapsina; an amoeboid phase, in the 

 Rhizochrysodina. 



Endogenous formation of a siliceous cyst wall is characteristic (247). As 



Fig. 4. 5. A, B. CycJonexis annularis Stokes, lateral and surface views; x720 

 (after S.). C. Synura uvella Ehrbg.; x310 (after Stein). D. Chrysosphaerella 

 longispina Laiiterborn; x540 (after L.). 



encystment begins in Uroglena sonaica (Fig. 4. 7, H-J) the fiagella are 

 resorbed and the organism, packed with fat globules, becomes approxi- 

 mately spherical. Within the cytoplasm, a thin membrane is laid down. 

 This membrane gradually increases in thickness, a pore is differentiated, 

 and surface decorations are added. The development of a plug finally 

 closes the pore, separating the endocystic from the subsequently discarded 

 ectocystic protoplasm (50). The plug may or may not be siliceous in dif- 

 ferent species. In either case, the ping is either dislodged or dissolved in 

 excystment. Encystment in Ochromo7ias granularis (66) resembles that in 

 Uroglena. In certain other types, such as Chromulina (67), part or all 



