364 PROTOZOOLOGY 



Genus Raphidiophrys Archer. Spherical; mucilaginous envelope 

 with spindle-shaped or discoidal spicules which extend normally 

 outwards along pseudo})odia; nucleus and endoplasm eccentric; 

 solitary or colonial; fresh water. Several species. 



R. pallida Schulze (Fig. 165, d). Outer gelatinous envelope 

 crowded with curved lenticular spicules, forming accumulations 

 around pseudopodia; ectoplasm granulated; nucleus eccentric; 

 contractile vacuoles; axial filaments arise from the central 

 granule; solitary; diameter 50-60/i; nucleus 12-15/u in diameter; 

 spicules 20yu long; among vegetation in still fresh water. 



Genus Raphidocystis Penard. Spicules of various forms, but 

 unlike those found in the last genus. 



R. tuhifera P. (Fig. 165, e). Spicules tubular with enlarged 

 extremity; diameter about 18/x; envelope 25//; fresh water. 



Genus Wagnerella Mereschkowsky. Spherical, supported by a 

 cylindrical stalk with an enlarged base; small siliceous spicules; 

 nucleus in the base of stalk; multiplication by budding. 



W. borealis M. (Fig. 165, /). About ISO/t in diameter; stalk 

 often up to 1.1 mm. long; salt water. 



Genus Pinaciophora Greeff. Spherical; outer envelope com- 

 posed of circular discs, each being perforated with 19 minute 

 pores; cytoplasm reddish; fresh water. 



P. fluviatilis G. (Fig. 165, g). Diameter 45-50jU, but somewhat 

 variable; in freshwater ponds. 



Family 8 Clathrulinidae Glaus 



Genus Clathrulina Cienkowski. Envelope spherical, homo- 

 geneous, with numerous regularly arranged openings; with a 

 stalk; protoplasm central, not filling the capsule; nucleus central; 

 pseudopodia numerous, straight or forked, granulated; fresh 

 water. 



C. elegans C. (Fig. 166, a). Envelope colorless to brown, per- 

 forated by numerous comparatively large circular or polygonal 

 openings; 1 or more contractile vacuoles; nucleus central; diame- 

 ter 60-90/i; openings 6-10/jl; stalk 2-4 times the diameter of 

 envelope by 3-4/t wide; solitary or colonial; among vegetation 

 in ponds. 



Genus Hedriocystis Hertwig et Lesser. Envelope spherical, 

 openings minute, surrounded by polyhedral facets or ridges; with 

 stalk; solitary or colonial; fresh water. 



