154 The Mastigophora 



Four flagella are present in Carteria, Chlorobrachis, Fortiella, Malleochloris, Platy- 

 monas, Spirogonium, and Tetrablepharis; one flagellum in Chloroceras and Seleno- 

 chloris: two flagella in other genera. In some cases, a knowledge of life-cycles is 

 essential for assignments to genera. In Nautococcus, for example, there is a typical 

 flagellate stage in addition to the floating stage without flagella (Fig. 4. 28, I, J); in 

 Stylosphaeridium, the corresponding non-flagellated stage is epiphytic on filamentous 

 algae. Cytological descriptions are available for Chlamydomonas (129), Chlorogonium 

 (102), Parapolytoma (121), and Polytoma (78, 110). 



Fig. 4. 28. A, B. Fission in Chlamydomonas seriata Pascher (schematic, 

 after P.). C, D. Rotation of the chromatophore at the beginning of fission 

 in Chlamydomonas nasuta; schematic (after Kater). E. Lobomonas roslrata 

 Hazen; xl750 approx. (after H.). F. Brachiomonas ivestiana Pascher; .x690 

 approx. (after P.). G. Chlamydomonas umbonata Pascher, xl330 approx. 

 (after P.). H. Tussetia polytomoides Pascher, xl400 approx. (after P.). I, J. 

 Nautococcus mammilatus Korshikofl^; stage with umbrella-like float, xl250; 

 flagellate stage, x2500 (after K.). K, L. Scourfieldia complanata West, views 

 of l)road and narrow surfaces; xl725 approx. (after W.). M. Hyalogonium 

 klebsii Pascher, x500 approx. (after P.). N. Platymonas tetrathele West, 

 xl430 (after Carter). O. Carteria coccifera Pascher, x960 (after P.). 



