PHYTOMONADINA 201 



Genus Pandorina Bory. Spherical or subspherical colony of 

 usually 16 (sometimes 8 or 32) biflagellate individuals, closely 

 packed within a gelatinous, but firm and thick matrix; individuals 

 often angular; with stigma and chromatophores ; asexual repro- 

 duction through simultaneous division of component indi\dduals; 

 anisogamy preceded by division of each cell into 16 to 32 gametes; 

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

 species. 



P. morum (Mtiller) (Figs. 72; 94,/). Cells 8-17ju long; colony 

 20-40m, up to 250^1 in diameter; ponds and ditches. 



Genus Mastigosphaera Schewiakoff . Similar to Pandorina; but 

 individual with a single flagellum which is 3.5 times the body 

 length; fresh water. 



M. gobii S. (Fig. 94, g). Individual 9m long; colony 30-33m. 



Genus Eudorina Ehrenberg. Spherical or ellipsoidal colony of 

 usually 32 or sometimes 16 spherical cells; asexual reproduction 

 similar to that of Pandorina; isogamy with 32-64 spherical green 

 macrogametes and numerous clustered microgametes ; reddish 

 zygote with a smooth wall; fresh water. 



E. elegans E. (Figs. 73; 94, h). Cells 10-24/^ in diameter; colony 

 40-150ai in diameter; in ponds, ditches and lakes. 



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, and are located within a 

 gelatinous matrix; fresh water. 



P. illinoisensis Kofoid (Figs. 31, 6, c; 94, 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; vegeta- 

 tive cells 10-1 6m in diameter; reproductive cells 19-25m in diame- 

 ter; colony up to 160yu by 130^. 



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

 1/2-2/3 are reproductive cells; vegetative cells 13-15/x; reproduc- 

 tive cells up to 27/x; colony up to 450/x, both in diameter. 



References 



Bold, H. C. 1938 Notes on Maryland Algae. Bull. Torrey Bot. 



Club., Vol. 65. 

 Crow, W. B. 1918 The classification of some colonial chlamy- 



domonads. New Phytologist, Vol. 17. 

 Dangeard, p. 1900 Observations sur la structure et le develop- 



pement du Pandorina morum. Le Botaniste, Vol. 7. 



