94 HANDBOOK OF PROTOZOOLOGY 



than 10 microns long. In the foraminiferan, Peneroplis per- 

 tusus. 



Genus Chilomonas Ehrenberg. Similar to Cryptomonas in 

 general body form and structure, but colorless because of the 

 absence of chromatophores. With numerous assimilation pro- 

 ducts, amyloid bodies. Saprozoic. 



Chilomonas Paramecium Ehrenberg (Fig. 32, d). Length 

 30 to 50 microns. Very common in stagnant water and also in 

 hay infusion. Widely distributed. 



Genus Cyathomonas Fromentel. Body small, somewhat 

 oval, much flattened. Anterior end obliquely truncate. W'ith 

 two equal or subequal anterior flagella. Colorless. The nucleus 

 central ; contractile vacuole usually anterior. A row of refractile 

 granules close and parallel to the anterior margin of the body. 

 Asexual reproduction by longitudinal fission. In stagnant water 

 and infusion, 



Cyathomonas truncata Ehrenberg (Fig. 32, e). Length about 

 20 microns. Often in infusion. 



Genus Cryptochrysis Pascher. Furrow indistinct. Chroma- 

 tophore brownish or olive-green. Some lose flagella and may 

 assume amoeboid form. Two equal flagella. 



Cryptochrysis commutata Pascher (Fig. 32, /). About 20 

 microns long. Fresh water. 



Family 2 Nephroselmidae Pascher 



Body reniform; with lateral equatorial furrow. Two 

 flagella arising from the furrow, one directed anteriorly and the 

 other posteriorly. Several genera. 



Genus Protochrysis Pascher. Body with a distinct furrow, 

 but without cytopharynx. A stigma at the base of the flagella. 

 One or two chromatophores, brownish yellow. Pyrenoid cen- 

 tral; two contractile vacuoles. Fission seems to take place 

 during the resting stage. 



Protochrysis phaeophycearum Pascher (Fig. 32, g). Body 

 about 17 to 20 microns long. 



Genus Nephroselmis Stein. Furrow indistinct; no stigma; 

 cytopharynx distinct. Chromatophores discoid, brownish green 

 in color. A central pyrenoid; with reddish globules. 



