412 PROTOZOOLOGY 



Family 6 Clathrellidae Poche 



Genus Clathrella Penard. Envelope distinct, polygonal; surface 

 with uniform alveoli with interalveolar portion extending out; en- 

 velope appears to be continuous, but in reality formed by a series 

 of cup-like bodies; contractile vacuole large; voluminous nucleus 

 eccentric; filopodia straight, some bifurcated, arising between 

 "cups." 



C. foreli P. (Fig. 192, a). Envelope about 40-55^ in diameter; 

 fresh water. 



Family 7 Acanthocystidae Glaus 



Genus Acanthocystis Garter. Spherical; siliceous scales, arranged 

 tangentially and radiating siliceous spines with pointed or bifur- 

 cated ends; nucleus and endoplasm eccentric; a distinct central 

 granule in which the axial filaments terminate. Several species. 



A. aculeata Hertwig and Lesser (Fig. 192, h). Tangential scales 

 stout and pointed; spines curved and nail-headed; cytoplasm grey- 

 ish; a single contractile vacuole; diameter 35-40/*; spines about 1/3 

 the body diameter; in fresh water. 



Genus Pompholjrxophrys Archer. Spherical; outer mucilaginous 

 envelope with minute colorless spherical granules arranged in con- 

 centric layers; nucleus eccentric; contractile vacuoles; pseudopodia 

 long, straight, acicular; fresh water. 



P. punicea A. (Fig. 192, c). Body colorless or reddish, with usually 

 many colored granules and green or brown food particles; nucleus 

 large, eccentric; solitary, active; diameter 25-35/1; outer envelope 

 5-10/1 larger; in pools. 



Genus Raphidiophrys Archer. Spherical; mucilaginous envelope 

 with spindle-shaped or discoidal spicules which extend normally 

 outwards along pseudopodia; nucleus and endoplasm eccentric; 

 solitary or colonial; fresh water. Several species. 



R. pallida Schulze (Fig. 192, d). Outer gelatinous envelope 

 crowded with curved lenticular spicules, forming accumulations 

 around pseudopodia; ectoplasm granulated; nucleus eccentric; con- 

 tractile vacuoles; axial filaments arise from the central granule; 

 solitary; diameter 50-60/i; nucleus 12-15/t in diameter; spicules 20/i 

 long; among vegetation in still fresh water. 



Genus Raphidocystis Penard. Spicules of various forms, but un- 

 like those found in the last genus. 



R. tuhifera P. (Fig. 192, e). Spicules tubular with enlarged extrem- 

 ity; diameter about 18/t; envelope 25/t; fresh water. 



Genus Wagnerella Mereschkowsky. Spherical, supported by a 



