252 HANDBOOK OF PROTOZOOLOGY 



ing accumulations around the pseudopodia. Ectoplasm granu- 

 lated; nucleus eccentric. Contractile vacuoles. Axial filaments 

 arise from the central granule. Solitary. Diameter 50 to 60 

 microns. In vegetation in still water. 



Genus Raphidiocystis Penard. Spicules unlike those oc- 

 curring in the last genus. With radiating needle-like spicules. 



Raphidiocystis tubifera Penard (Fig. 100, d). With charac- 

 teristic spicules. Body diameter about 18 microns; envelope 25 

 microns. Fresh water. 



Genus Wagnerella Mereschkowsky. Body spherical, sup- 

 ported by a cylindrical stalk with an enlarged base. Small 

 silicious spicules. The nucleus is located in the base of the 

 stalk. Reproduction through budding. 



Wagnerella borealis Mereschkowsky (Fig. 100, e). Body up 

 to 180 microns in diameter. Stalk often up to 1.1 mm. in 

 length. In marine water. 



Genus Pinaciophora Greeff. Spherical. Outer envelope is 

 composed of imbricated circular discs, each being perforated 

 with nineteen minute pores. Cytoplasm reddish. One species. 



Pinaciophora fluviatilis Greeff (Fig. 100,/). Diameter 45 

 to 50 microns, but somewhat variable. In ponds. 



Suborder 4 Desmothoraca Hertwig and Lesser 



Homogeneous capsule, with or without perforation, often 

 with a pedicel or stalk. 



Genus Clathrulina Cienkowski. Envelope spherical, homo- 

 geneous, with numerous openings regularly arranged. With a 

 stalk. Body protoplasm central, not filling the capsule. The 

 single nucleus centrally located. Pseudopodia numerous, 

 straight or forked, granular. A few species. 



Clathrulina elegans Cienkowski (Fig. 101, a). Envelope 

 colorless to brown, perforated by numerous comparatively 

 large openings which are circular or polygonal. One or more 

 contractile vacuoles. Nucleus central. Diameter 30 to 90 

 microns; openings 6 to 10 microns; stalk 120 to 350 microns 

 long by 3 or 4 microns wide. Solitary or colonial. Among 

 vegetation in ponds and pools. 



Genus Hedriocystis Hertwig and Lesser. Envelope spheri- 



