SARCODINA, PROTEOMYXA 423 



to 80/x or more; pseudopodia 400/x long or longer. Cienkowski main- 

 tained that this was a moneran. 



Genus Penardia Cash. When inactive, rounded or ovoid; at other 

 times expanded; exceedingly mobile; endoplasm chlorophyll-green 

 with a pale marginal zone; filopodia, branching and anastomosing, 

 colorless; nucleus inconspicuous; one or more contractile vacuoles, 

 small; fresh water. 



P. mutabilis C. (Fig. 177, /). Resting form 90-100/x in diameter; 

 extended forms (including pseudopodia) 300-400/x long. 



Genus Hyalodiscus Hertwig and Lesser. Discoid, though outline 

 varies; endoplasm reddish, often vacuolated and sometimes shows 

 filamentous projections reaching body surface; a single nucleus; 

 ectoplasmic band of varying width surrounds the body completely; 

 closely allied to Vampyrella; fresh water. 



H. rubicundus H. and L. (Fig. 177, g). 50-80/x by about 30ju; 

 polymorphic; when its progress during movement is interrupted by 

 an object, the body doubles back upon itself, and moves on in 

 some other direction; freshwater ponds among surface vegetation. 



Genus Leptomyxa Goodey. Multinucleate, thin, amoeboid or- 

 ganisms; multinucleate cysts formed by condensation of protoplasm; 

 free-living in soil (Goodey, 1915). 



L. reticulata G. (Fig. 178, a-c). Body composed of a thin trans- 

 parent protoplasm; when fully extended, 3 mm. or more in length; 

 superficially resembles an endosporous mycetozoan, but no reversi- 

 ble cytoplasmic movement; multinucleate with eight to 20 to several 

 hundred nuclei; nuclei, 5-6/z in diameter, with a large endosome; 

 nuclear division simultaneous, but not synchronous; plasmotomy; 

 plasmogamy; cysts multinucleate, by local condensation of proto- 

 plasm; widely distributed in British soil (Singh, 1948, 1948a). 

 McLennan (1930) found a similar organism in and on the root of 

 diseased hops in Tasmania. 



Genus Megamoebomyxa Nyholm. Extremely large amoeboid or- 

 ganism; when contracted, lobulate, with adhering detritus; when 

 cultured at 8-10°C. on debris, filopodia are formed and form-change 

 occurs; lobate during locomotion; "nutrient chiefly detritus"; Ma- 

 rine. One species (Nyholm, 1950). 



M. argillobia N. (Fig. 178, d). An opaque white organism; up to 

 25 mm. long; polymorphic; in marine sediment, rich in debris at the 

 depth of 45-70 in.; Gullmar Fjord, Sweden. 



Genus Reticulomyxa Nauss. Highly polymorphic, multinucleate 

 amoeboid organism; rhizopodia radiating from a central mass of un- 

 differentiated granular protoplasm with many non-contractile vacu- 



