476 PROTOZOOLOGY 



Genus Schultzella Rhumbler. Test thin, delicate, difficult to 

 recognize in life, easily broken at any point for formation of pseudo- 

 podia which branch and anastomose; irregularly rounded; without 

 foreign material; salt water. 



S. diffluens (Grubler) (Fig. 199, g). Cytoplasm finely granulated; 

 opaque, colorless; with oil droplets, vacuoles and numerous small 

 nuclei ; up to 220/j. in diameter. 



Genus Myxotheca Schaudinn. Amoeboid; spherical or hemi- 

 spherical, being flattened on the attached surface; a thin pseudo- 

 chitinous test with foreign bodies, especially sand grains; pseudo- 

 podia anastomosing; salt water. Nucleus (Foyn, 1936). 



M. arenilega S. (Fig. 200, d). Test yellow, with loosely attached 

 foreign bodies; cytoplasm bright red due to the presence of highly 

 refractile granules; 1-2 nuclei, 39-75ju in diameter; body diameter 

 160-560/z. 



Genus Dactylosaccus Rhumbler. Test sausage-shape and vari- 

 ously twisted; pseudo podia filiform, anastomosing; salt water. 



D. vermiformis R. (Fig. 200, e). Test smooth; pseudo podia rise 

 from small finger-like projections; 1-2 nuclei; body 4 mm. by 340m ; 

 salt water. 



Genus Boderia Wright. Body form changeable; often spherical, 

 but usually flattened and angular; filopodia long; test extremely 

 delicate, colorless; salt water. 



B. turneri W. (Fig. 200, /). Body brown to orange; active cyto- 

 plasmic movement; 1-10 nuclei ; multiple division(?) ; 1.56-6.25 mm. 

 in diameter; in shallow water. 



Family 2 Arcellidae Schultze 



Genus Arcella Ehrenberg. Test transparent, chitinous, densely 

 punctated; colorless to brown (when old); in front view circular, 

 angular, or stellate; in profile plano-convex or semicircular; vari- 

 ously ornamented; aperture circular, central, inverted like a funnel; 

 protoplasmic body does not fill the test and connected with the latter 

 by many ectoplasmic strands; slender lobopodia, few, digitate, sim- 

 ple or branched; 2 or more nuclei; several contractile vacuoles; fresh 

 water. Numerous species. Taxonomy and morphology (Deflandre, 

 1928); variation and heredity (Jollos, 1924). 



A. vulgaris E. (Fig. 201, a, b). Height of test about 1/2 the diame- 

 ter; dome of hemispherical test evenly convex; aperture circular, 

 central; colorless, yellow, or brown; protoplasmic body conforms 

 with the shape of, but does not fill, the test; lobopodia hyaline; 2 

 vesicular nuclei; several contractile vacuoles; test 30-100/x in dia- 



