414 PROTOZOOLOGY 



Genus Pinaciophora Greeff. Spherical; outer envelope composed 

 of circular discs, each being perforated with 19 minute pores; cyto- 

 plasm reddish ; fresh water. 



P. fluviatilis G. (Fig. 192, g). Diameter 45-50/i, but somewhat 

 variable; in freshwater ponds. 



Family 8 Clathrulinidae Glaus 



Genus Clathrulina Cienkowski. Envelope spherical, homogeneous, 

 with numerous regularly arranged openings; with a stalk; proto- 

 plasm central, not filling the capsule; nucleus central; pseudo podia 

 numerous, straight or forked, granulated; fresh water. 



C. elegans C. (Fig. 193, a). Envelope colorless to brown, perforated 

 by numerous comparatively large circular or polygonal openings; 1 

 or more contractile vacuoles; nucleus central; diameter 60-90/i, 

 openings 6-10)u; length of stalk 2-4 times the diameter of envelope, 

 3-4)u wide; solitary or colonial; among vegetation in ponds. 



Genus Hedriocystis Hertwig and Lesser. Envelope spherical, 

 openings minute, surrounded by polyhedral facets or ridges; with 

 stalk; solitary or colonial; fresh water. 



H. reticulata Penard (Fig. 193, 6). Envelope colorless or pale 

 yellow, facets regularly polygonal with raised borders; stalk solid, 

 straight; nucleus central; 1 contractile vacuole; each pseudo- 

 podium arises from a pore located in the center of a facet; solitary; 

 capsule about 25;u in diameter; body about I2fj. in diameter; stalk 

 about 70/1 by l.S/t; in marshy pools. 



Genus Blaster Grimm. Envelope spherical, delicate, penetrated 

 by numerous more or less large pores; without stalk; pseudopodia 

 many, straight filose. 



E. greeffi G. (Fig. 193, c). Diameter of envelope 20/1; envelope 

 delicate, colorless; many pseudopodia; in peaty soil. 



Genus Choanocystis Penard. Spherical envelope with perforations 

 which possess conical borders; openings of cones provided with 

 funnel-like expansions, edges of which nearly touch one another; 

 fresh water. 



C. lepidula P. (Fig. 193, d). Diameter 10-13/i; envelope delicate; 

 1 or more contractile vacuoles; pseudopodia very long. 



Family 9 Myriophryidae Poche 



Genus Myriophrys Penard. Spherical or ovoid, covered with a 

 protoplasmic envelope containing scales (?), surrounded by numer- 

 ous fine processes; endoplasm vesicular; a large nucleus eccentric; a 



