240 



PROTOZOOLOGY 



rily sedentary forms; if temporarily freed, organisms swim with 

 fiagellum directed backward; holozoic on bacteria or saprozoic; 

 often colonial; free-living in fresh water. 



Genus Codosiga Kent (Codonocladium Stein; Astrosiga Kent). 

 Individuals clustered at end of a simple or branching stalk; fresh 

 water. 



C. utriculus Stokes (Fig. 109, b). About ll/j. long; attached to 

 freshwater plants. 



C. disjuncta (Fromentel) (Fig. 109, c). In stellate clusters; cells 

 about 15/x long; fresh water. 



Genus Monosiga Kent. Solitary; with or without stalk; occa- 

 sionally with short pseudopodia; attached to freshwater plants. 

 Several species. 



Fig. 109. a, Phalansterium digitatum, X540 (Stein); b, Codosiga 

 utriculus, X1340 (Stokes); c, C. disjuncta, X400 (Kent); d, Monosiga 

 ovata, X800 (Kent); e, M. rohusta, x770 (Stokes); f, Desmarella 

 nioniliformis, X800 (Kent) ; g, Proiospon^ia haeckeli, X400 (Lemmer- 

 mann); h, Sphaeroeca volvox, X890 (Lenimermann) ; i, Diplosiga 

 francei, X400 (Lemmermann) ; j, D. socialis, X670 (Franc6). 



