MASTIGOPHORA, CHRYSOMONADINA 179 



Family 3 Ochromonadidae Pascher 



With 2 unequal flagella; body has no pellicle and is plastic; 

 contractile vacuoles simple; with or without dehcate test; solitary 

 or colonial; free-swimming or attached. 



Genus Ochromonas Wyssotzki. Solitary or colonial; body 

 surface delicate; posterior end often drawn out for attachment; 

 1-2 chromatophores; usually with a stigma; encystment; fresh 

 water. 



0. mutdbilis Klebs (Fig. 87, a). Ovoid to spherical; plastic; 

 15-30m by 8-22/x. 



0. ludihunda Pascher (Fig. 87, 6). Not plastic; 12-17ai by 

 6-1 2m. 



Genus Uroglena Ehrenberg. Spherical or ovoidal colony, com- 

 posed of ovoid or ellipsoidal individuals arranged on periphery 

 of a gelatinous mass; all individuals connected with one another 

 by gelatinous processes running inward and meeting in a point; 

 with a stigma and a plate-like chromatophore; asexual reproduc- 

 tion of individuals by longitudinal fission, that of colony by 

 bipartition; cysts spherical with spinous projections, and a long 

 tubular process; fresh water. One species. 



U. volvox E. (Fig. 87, c). Cells 12-20^ by S-IBm; colony 40- 

 400/z in diameter; in standing water. 



Genus Uroglenopsis Lemmermann. Similar to Uroglena, but 

 individuals without inner connecting processes. 



U. americana (Calkins) (Fig. 87, d). Each cell with one chro- 

 matophore; 5-8jU long; flagellum up to 32/i long; colony up to 300/i 

 in diameter; when present in abundance, the organism gives an 

 offensive odor to the water (Calkins). 



U'. europaea Pascher. Similar to the last-named species; 

 but chromatophores 2; cells up to 7^ long; colony 150-300/^ in 

 diameter. 



Genus Cyclonexis Stokes. Wheel-like colony, composed of 10- 

 20 wedge-shaped individuals; young colony funnel-shaped; chro- 

 matophores 2, lateral; no stigma; reproduction and encystment 

 unknown; fresh water. 



C. annularis S. (Fig. 87, e). Cells ll-14;u long; colony 25-30/i 

 in diameter; in marshy water with sphagnum. 



Genus Dinobryon Ehrenberg. Sohtary or colonial; individuals 

 with vase-like, hyahne, but sometimes, yellowish cellulose test, 

 drawn out at its base; elongated and attached to the base of test 



