290 PROTOZOOLOGY 



through simultaneous division of component individuals; anisog- 

 amy; zygotes colored and covered by a smooth wall; fresh water. 

 One species. 



P. morum (Miiller) (Figs. 117, /). Cells 8-17/z long; colony 20- 

 40/x, up to 250/z in diameter; ponds and ditches. 



Genus Mastigosphaera Schewiakoff. Similar to Pandorina; but 

 individuals with a single flagellum which is 3.5 times the body length; 

 fresh water. 



M. gobii S. (Fig. 117, g). Individual 9m long; colony 30-33/*. 



Genus Eudorina Ehrenberg. Spherical or ellipsoidal colony of 

 usually 32 or sometimes 16 spherical cells; asexual reproduction 

 similar to that of Pandorina; sexual reproduction with 32-64 spheri- 

 cal green macrogametes and numerous clustered microgametes which 

 when mature, unite with the macrogametes within the colony; red- 

 dish zygotes with a smooth wall; fresh water. Colony formation 

 (Hartmann, 1924). 



E. elegans E. (Fig. 117, h). Cells 10-24^ in diameter; colony 40- 

 150 fx in diameter; in ponds, ditches and lakes. Culture and morphol- 

 ogy (Hartmann, 1921); response to light (Luntz, 1935). 



Genus Pleodorina Shaw. Somewhat similar to Eudorina, being 

 composed of 32, 64, or 128 ovoid or spherical cells of 2 types: small 

 somatic and large generative, located within a gelatinous matrix; 

 Sexual reproduction similar to that of Eudorina; fresh water. 



P. illinoisensis Kofoid (Figs. 32, b, c; 117, i). 32 cells in ellipsoid 

 colony, 4 vegetative and 28 reproductive individuals; arranged in 

 5 circles, 4 in each polar circle, 8 at equator and 8 on either side of 

 equator; 4 small vegetative cells at anterior pole; vegetative cells 

 10-16/x in diameter; reproductive cells 19-25/x in diameter; colony 

 up to 160m by 130/z. 



P. californica S. Spherical colony with 64 or 128 cells, of which 

 1/2-2/3 are reproductive cells; vegetative cells 13-1 5m; reproductive 

 cells up to 27/x; colony up to 450/x, both in diameter. Variation (Tif- 

 fany, 1935); in Ukraine (Swirenko, 1926). 



References 



Aragao, H. B.: (1910) Untersuchungen iiber Polytomella agilis n.g., 



n. sp. Mem. Inst. Oswaldo Cruz, 2:42. 

 Bold, H. C: (1938) Notes on Maryland algae. Bull. Torrey Bot. 



Club., 65:293. 

 Conrad, W. : (1930) Flagellates nouveaux ou peu connus. I. Arch. 



Protist., 70:657. 

 Crow, W. B.: (1918) The classification of some colonial Chlamy- 



domonads. New Phytol., 17:151. 



