274 PROTOZOOLOGY 



nant water. Cytology (Mast and Doyle, 1935; Hollande, 1942; 

 Dragesco, 1951); bacteria-free culture (Mast and Pace, 1933); me- 

 tabolism (Mast and Pace, 1929; Pace, 1941); growth substances 

 (Pace, 1944, 1947; Mast and Pace, 1946); effects of vitamins (Pace, 

 1947). 



C. oblonga Pascher. Oblong; posterior end broadly rounded; 20- 

 50/i long. 



Genus Chrysidella Pascher. Somewhat similar to Cryptomonas- 

 but much smaller-, yellow chromatophores much shorter; those oc, 

 curring in Foraminifera or Radiolaria as symbionts are known as 

 Zooxanthellae. Several species. 



C. schaudinni (Winter) (Fig. Ill, c, d). Body less than 10m long; in 

 the foraminiferan Peneroplis pertusus. 



Genus Cyathomonas Fromentel. Body small, somewhat oval; 

 without chromatophores; much compressed; anterior end obliquely 

 truncate; with 2 equal or subequal anterior flagella; colorless; nu- 

 cleus central; anabolic products, stained red or reddish violet by 

 iodine; contractile vacuole usually anterior; a row of refractile 

 granules, protrichocysts, close and parallel to anterior margin of 

 body; asexual reproduction by longitudinal fission; holozoic; in stag- 

 nant water and infusion. One species. 



C. truncata Ehrenberg (Fig. Ill, e). 15-25ju by 10-15/i. 



Genus Cryptochrysis Pascher. Furrow indistinctly granulated; 

 2 or more chromatophores brownish, olive-green, or dark green, 

 rarely red; pyrenoid central; 2 equal flagella; some lose flagella and 

 may assume amoeboid form ; fresh water. 



C. commutataV. (Fig. Ill, /). Bean-shaped; 2 chromatophores; 

 19/x by 10m. 



Genus Rhodomonas Karsten. Furrow granulated; chromatophore 

 one, red (upon degeneration the coloring matter becomes dissolved 

 in water) ; pyrenoid central ; fresh water. 



R. lens Pascher and Ruttner (Fig. Ill, g). Spindle-form; about 16m 

 long; in fresh water. 



Family 2 Nephroselmidae Pascher 



Body reniform; with lateral equatorial furrow; 2 flagella arising 

 from furrow, one directed anteriorly and the other posteriorly. 



Genus Nephroselmis Stein. Reniform; flattened; furrow and 

 cytopharynx distinct; no stigma; 1-2 chromatophores, discoid, 

 brownish green; nucleus dorsal; a central pyrenoid; 2 contractile 

 vacuoles; with reddish globules; fresh water. 



N. olvacea S. (Fig. Ill, h). 20-25m by 15m- 



