234 HANDBOOK OF PROTOZOOLOGY 



Genus Rhynchogromia Rhumbler. Test rigid or flexible, 

 chitinous, and elongate, with foreign bodies. Aperture terminal 

 or slightly oblique. Finely granulated cytoplasm fills the test. 

 Nucleus one or more. One to several contractile vacuoles. 

 Pseudopodia arise from a peduncle; numerous, branching or 

 anastomosing; often enveloping the test. 



Rhynchogromia nigricans (Penard) (Fig. 93, d). Test large; 

 circular in cross-section. With a single nucleus. Length 220 

 to 400 microns. In submerged moss in ponds. 



Genus Diplophrys Barker. Test thin, spherical; aperture 

 two, located at opposite poles. Cytoplasm colorless; a single 

 nucleus; several contractile vacuoles. Filopodia radiating. One 

 species. 



Diplophrys archeri Barker (Fig. 93, e). Invariably with one, 

 two, or three colored oil droplets. Pseudopodia highly attenu- 

 ated, radiating, straight or branched. Multiplication into two 

 or four daughter individuals. Solitary or colonial. Diameter 8 

 to 20 microns. In submerged plants in fresh water. 



Genus Amphitrema Archer. Test ovoid, symmetrical, com- 

 pressed; composed of a transparent membrane, with or without 

 adherent foreign bodies. Aperture two, located at opposite 

 poles. The endoplasm contains Zoochlorellae. A central nuc- 

 leus; one to several contractile vacuoles. Straight filopodia, 

 sparsely branched, radiating. Several species. 



Amphitrema flavum (Archer) (Fig. 93,/). Test chitinoid, 

 brown, cylindrical with equally rounded ends in front view; 

 elliptical in profile; ovoid with a small central oval aperture in 

 end-view. Size about 45 to 80 microns long by 23 to 45 microns 

 broad. In Sphagnum. 



Genus Lecythium Hertwig and Lesser. Test thin, flexible, 

 colorless. Aperture elastic and terminal. Colorless cytoplasm 

 fills the test. A large nucleus located posteriorly. Numerous 

 filopodia, long, branching, not anastomosing. 



Lecythium hyalinum (Ehrenberg) (Fig. 94, a). Spheroidal. 

 Aperture circular with a short flexible neck. A single contractile 

 vacuole. Diameter 20 to 45 microns. In submerged vegetation. 



Genus Pseudodifflugia Schlumberger. Test ovoid, usually 

 rigid, with foreign bodies; circular or elliptical in cross-section. 

 Aperture terminal. Granulated cytoplasm colorless or greyish. 



