PHYTOMONADINA 189 



Genus Chlamydomonas Ehrenberg. Spherical, ovoid or elon- 

 gated; sometimes flattened; 2 flagella; membrane often thickened 

 at anterior end; a large chromatophore, containing one or more 

 pyrenoids; stigma; a single nucleus; 2 contractile vacuoles an- 

 terior; asexual reproduction and palmella formation known; 

 sexual reproduction isogamy or anisogamy; fresh water. Numer- 

 ous species. 



C. monadina Stein (Fig. 90, a-c). 15-30/i long; fresh water; 

 Landacre noted that the organisms obstructed the sand filters 

 used in connection with a septic tank, together with the diatom 

 Navicula. 



C. angulosa Dill. About 20^ by 12-15/i; fresh water. 



C. epiphytica Smith (Fig. 90, d). 8-9 fj, by I-Sjjl; in freshwater 

 lakes. 



C. glohosa Snow (Fig. 90, e). Spheroid or ellipsoid; 5-7/^ in 

 diameter; in freshwater lakes. 



C. gracilis Snow (Fig. 90,/). 10-13^ by 5-7m; fresh water. 



Genus Haematococcus Agardh {Sphaerella Sommerfeldt). 

 Spheroidal or ovoid with a gelatinous envelope; chromatophores 

 peripheral and reticulate, with 2-8 scattered pyrenoids; several 

 contractile vacuoles; haematochrome frequently abundant in 

 both motile and encysted stages; asexual reproduction in motile 

 form; sexual reproduction isogamy; fresh water. 



H. pluvialis (Flotow) (Figs. 38; 90, g). Oval or elhpsoid; wdth 

 numerous radial cytoplasmic processes; chromatophores thick- 

 walled; body up to 60ju by SO^u; stigma about 13yu long; fresh 

 water; according to Reichenow (1909), the haematochrome dis- 

 appears under experimental condition if the culture medium is 

 rich in nitrogen and phosphorus. 



Genus Sphaerellopsis Korschikoff (Chlamydococcus Stein). 

 With gelatinous envelope which is usually ellipsoid with rounded 

 ends; body elongate fusiform or pyriform, no protoplasmic 

 processes to envelope; 2 equally long flagella; chromatophore 

 large; a pyrenoid; with or without stigma; nucleus in anterior 

 half; 2 contractile vacuoles; fresh water. 



,S. fluviatilis (Stein) (Fig. 90, h). 14-30^ by 10-20^; fresh water. 



Genus Brachiomonas Bohlin. Lobate; with horn-like processes, 

 all directed posteriorly; contractile vacuoles; ill-defined chro- 

 matophore; pyrenoids; with or without stigma; sexual and 

 asexual reproduction; fresh, brackish or salt water. 



