MASTIGOPHORA, CHRYSOMONADINA 181 



D. sertularia E. (Fig. 87,/). 30-44^ by 10-14^. 



D. divergens Imhof. 31-53^ long; great variation in different 

 localities (Ahlstrom). 



Genus Hyalobryon Laiiterborn. Solitary or colonial; individual 

 body structure similar to that of Dinobryon; lorica in some cases 

 tubular, and those of young individuals are attached to the ex- 

 terior of parent tests; fresh water. 



H. ramosum L. (Fig. 87, g). Lorica 50-70/i long by 5-9/x in 

 diameter; body up to 30^ by 5m; on vegetation in standing fresh 

 water. 



Genus Stylopyxis Bolochonzew. Solitary; body located at bot- 

 tom of a delicate stalked lorica with a wide aperture; 2 lateral 

 chromatoi)hores; fresh water. 



S. mucicola B. (Fig. 87, h). Lorica 17-18/x long; stalk about 33m 

 long; body 9-11m long; fresh water. 



Family 4 Coccolithidae Lohmann 



The members of this family, with a few exceptions, occur in 

 salt water only; with perforate (tremahth) or imperforate 

 (discohth) discs, composed of calcium carbonate; 1-2 flagella; 2 

 yellowish chromatophores; a single nucleus; oil drops and leuco- 

 sin ; holophytic. Examples : 



Pontos'phaera haeckeli Lohmann (Fig. 88, a). 



Discosphaera tuhijer Murray et Blackman (Fig. 88, 6). 



Family 5 Silicoflagellidae Borgert 



Exclusively marine planktons; with siliceous skeleton which 

 envelops the body. Example: Distephanus speculum (Mliller) 

 (Fig. 88, c). 



Suborder 2 Rhizochrysidina Pascher 



No flagellate stage is knoMai to occur; the organism possesses 

 pseudopodia; highly provisional group, based wholly upon the 

 absence of flagella; naked or with test; various forms; in some 

 species chromatophores are entirely lacking, so that the organisms 

 resemble some members of the Sarcodina. Several genera. 



Genus Rhizochrysis Pascher. Body naked and amoeboid; with 

 1-2 chromatophores; fresh water. 



R. scherffeli P. (Fig. 88, d). 10-14^ in diameter; 1-2 chromato- 

 phores; branching rhizopods; fresh water. 



Genus Chrysidiastrum Lauterborn. Naked; spherical; often 



