MASTIGOPHORA, CHRYSOMONADINA 257 



their fiagella and undergo division with development of mucilaginous 

 envelope and thus transform themselves often into large bodies 

 known as the palmella phase and undertake metabolic activities as 

 well as multiplication (Fig. 103). Asexual reproduction is, as a rule, 





m c w 



Qb — 1 



m \ / b 







Fig. 103. The life-cycle of Chromulina, X about 200 (Kiihn). a, encyst- 

 ment; b, fission; c, colony-formation; d, palmella-formation. 



by longitudinal division during either the motile or the palmella 

 stage. Incomplete separation of the daughter individuals followed 

 by repeated fission, results in numerous colonial forms mentioned 

 elsewhere (p. 174). Some resemble higher algae very closely. Sexual 

 reproduction is unknown in this group. Encystment occurs com- 

 monly; the cyst is often enveloped by a silicious wall possessing an 

 opening with a plug. Taxonomy (Doflein, 1923; Schiller, 1925a; 

 Pascher, 1926; Conrad, 1926; Scherffel, 1926; Hollande, 1952). 



The chrysomonads inhabit both fresh and salt waters, often occur- 

 ring abundantly in plankton. 



Motile stage dominant Suborder 1 Euchrysomonadina 



Palmella stage dominant 



Sarcodina-like; flagellate stage unknown 



Suborder 2 Rhizochrysidina (p. 267) 



With flagellate phase Suborder 3 Chrysocapsina (p. 269) 



Suborder 1 Euchrysomonadina Pascher 



With or without simple shell 



One flagellum Family 1 Chromulinidae (p. 258) 



2 flagella 



Fiagella equally long Family 2 Syncryptidae (p. 262) 



Flagella unequally long Family 3 Ochromonadidae (p. 264) 



With calcareous or silicious shell 



Bearing calcareous discs and rods. . . .Family 4 Coccolithidae (p. 266) 

 Bearing silicious skeleton Family 5 Silicoflagellidae (p. 267) 



