26o FRESH-WATER BIOLOGY 



135 (136) Flagellum single; two chromatophores. Chromulina Cienkowsky. 



Chrysomonas Stein is very closely related to this 



genus. Under the name Chrysomonas pulchra Stokes 



describes a species as follows; Body elongate-ovate or 



obovate, somewhat flexible, three times as long as 



broad, tapering and slightly constricted posteriorly, 



curved toward one side anteriorly. Frontal border ob- 



_ liquely excavate. Surface covered with minute hemi- 



FiG. 424. Chrysomoms pukkra. X 400. spherical elevations. Flagellum scarcely equalling the 



(Alter stomes.) j^^^^ j^^ length. Nucleus ovate. Contractile vacuoles 



two, anterior. Length 35 to 40 jx. Color green. Marsh 



water. 



136(135) Flagella, two; two chromatophores. . . Ochromonas Wysoiz^. 

 Representative species. . ... . Ochromonas sp. 



Species not identified. 



Fig. 425. Ochromonas sp. X 1000. (After Conn.) 



137 (134) Body enclosed by a membrane or lorica. . .... 138 



138(157) With a membrane. 139 



139 (146) Not forming colonies 140 



140 (141) With a close-fitting membrane of plates; flagellum single. 



Mallomonas Perty. 

 Representative species Mallomonas sp. 



Body elongated, enclosed by a membrane of overlapping 

 plates which bear long, slender spines. Two elongated, yel- 

 lowish-green chromatophores are within the body. 



Species not determined. 



Fig. 426. Mallomonas sp. X 500. (After Conn.) 



141 (140) With a firm cuticle ; two flagella 142 



142 (14s) Without chromatophores 143 



143 (144) Body oval, truncate or concave anteriorly, enclosing refractive 



bodies Cyathomonas de Fromentel. 



Representative species. Cyathomonas truncata deFiomtntel 1874. 



De Fromentel identified six or eight species, several of which are 



S^^sS-'t"^ but slightly distinguished from each other. Length 12 to 20 m 



Fresh water. 



FiG. 427. Cyatltommas tmncaUt. X uoo. (After Conn.) 



