74 



PROTOZOA 



CHAP. 



two in number, i.e. the nucleus divides into two, one of whid 



c. icic 



2-Nucleana 



3.Clarhrulina 



Fig. 20. Various forms of Heliozoa. In 3, a is the entire animal and b the flagellula ; 

 r.vac, contractile vacuole ; g, gelatinous investment ; nu, nucleus ; psd, pseudopodia ; 

 sk, siliceous skeleton ; sp, spicules. (From Parker and Haswell, after other authors.) 



goes to the surface as the first polar body, and the sister of thi 

 again divides to form a second polar body (which also passes to 



