PROTOMONADIDA 



149 



Genus Monas Ehrenberg. Known for a long time, but still 

 very incompletely. Body not longer than 20 microns, plastic 

 and actively motile ("dancing movement"). It attaches itself 

 often to foreign objects. 



Monas vulgaris (Cienkowski) (Fig. 55, a). Oval; with a 

 single nucleus. About 15 microns long. In stagnant water 

 and infusion. • 



Fig. 55 a. Monas vulgaris. X 750 (After Doflein). 



b. Slokesiella dissimilis. X375 (After Stokes). 



c. 5. leptostoma. X630 (After Stokes). 



d. A young colony of Dendromonas virgaria. X500 (After Stein). 



e. Cephalothamnium cyclopum. X325 (After Stein). 



f, g. Anthophysa vegetans. (After Stein), f, a colony (X170); 

 g, a single individual (X575). 

 h. Physomonas socialis. X500 (After Kent). 



Genus Stokesiella Lemmermann. Body is attached by a 

 fine cytoplasmic thread to a delicate and stalked vase-like test. 

 Fresh water. 



Stokesiella dissimilis (Stokes) (Fig. 55, h). Fresh water. 

 Solitary. Lorica about 28 microns long. 



Stokesiella leptostoma (Stokes) (Fig. 55, c). Fresh water. 

 Often in groups. Lorica about 16 microns long. 



Genus Dendromonas Stein. Colonial. Individuals without 



