108 ELECTRON-MICROSCOPIC STRUCTURE OF PROTOZOA 



species formerly called C. pusilla is a true uniflagellate but it has 

 been transferred to the green algae and to the new genus Micro- 

 ?nonas by Manton and Parke [I960].). The ultrastructure of 

 C. psammobia may be described here as generally typical of 

 chrysomonads (Text-fig. 6). 



Text-figure 6. Schematic drawing of a longitudinal section 

 through the anterior half of Chromulina psammobia. C, chloroplasts ; 

 G, Golgi body; I, invagination of the cell surface enclosing the 

 internal flagellum; N, nucleus; M, mitochondrion; S, stigma. The 

 kineto-rhizoplastic complex includes 1, the free flagellum; 2, its 

 kinetosome; 3, rhizoplast; 4, dense zone tentatively identified as 

 a centrosome. The kineto-stigmatic complex includes 5, the internal 

 flagellum lying above the stigma and 6, its kinetosome. From 

 Rouiller and Faure-Fremiet, 1958a. 



The cell body, up to 15 ^ in length, is limited by a typical unit 

 membrane, without any clearly evident outer coating or wall. 

 The cytoplasm is fibrogranular and encloses numerous mito- 

 chondria of typical protozoan microtubular structure, assorted 



