230 PROTOZOOLOGY 



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

 angular; with stigma and chromatophores; asexual reproduction 

 through simultaneous division of component individuals; 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 (Miiller) (Figs. 75; 100, /). Cells 8-17m long; colony 

 20-40/x, up to 250/i 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. gohii S. (Fig. 100, 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; red- 

 dish zygote with a smooth wall; fresh water. 



E. elegans E. (Figs. 76; 100, h). Cells 10-24^ in diameter; colony 

 40-1 50^1 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, located within a gelatinous matrix; 

 fresh water. 



P. illinoisensis Kofoid (Figs. 31, h, c; 100, 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 

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

 up to 160/x by 130m. 



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

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

 cells up to 27m; colony up to 450m, 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 and le developpe- 



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

 Elliott, A. M. 1934 Morphology and life history of Haematococcus 



pluvialis. Arch. f. Protistenk., Vol. 82. 

 Entz, G. Jr. 1913 Cytologische Beobachtungen an Polytoma uvella. 



Verb. Deutsch. Zool. Ges. Ver., Vol. 23. 



