ACTINOPODA, HELIOZOA 359 



lae; nucleus central; 1- many contractile vacuoles; axopodia 

 straight, numerous, axial filaments terminate at surface of the 

 nucleus; "sun animalcules"; fresh water. 



A. sol E. (Figs. 78; 163, b). Spherical; ectoplasm vacuolated; 

 endoplasm granulated with numerous small vacuoles; a large 

 central nucleus; soHtary but may be colonial when young; diame- 

 ter variable, average being 40-50ai; among plants in still fresh 

 water. Reproduction studied by Belaf (p. 156); Looper (1928) 

 studied its food reactions. 



A. vesiculata Penard. Ectoplasm with saccate secondary vesi- 

 cles, extending out of body surface between axopodia; nucleus 

 central, with many endosomes; 25-30^ in average diameter; 

 fresh water. 



Genus Actinosphaerium Stein. Spherical; ectoplasm consists 

 almost entirely of large vacuoles in one or several layers; endo- 

 plasm with numerous small vacuoles; numerous nuclei; axial 

 filaments end in the inner zone of ectoplasm. 2 species. 



A. eichhorni Ehrenberg (Figs. 6; 163, c). Numerous nuclei 

 scattered in the periphery of endoplasm; 2 or more contractile 

 vacuoles, large; axial filaments arise from a narrow zone of dense 

 cytoplasm at the border line between endoplasm and ectoplasm; 

 body large, diameter 200-300^, sometimes up to 1 mm.; nuclei 

 12-20/x in diameter; among vegetation in freshwater bodies. 



A. arachnoideum Penard. Ectoplasm irregularly vacuolated; 

 no distinct endoplasmic differentiation; nuclei smaller in number; 

 pseudopodia of 2 kinds; one straight, very long and the other 

 fihform, and anastomosing; 70-80/^ in diameter. 



Genus Camptonema Schaudinn. Spheroidal; axial filaments of 

 axopodia end in nuclei about 50 in number; (contractile?) vacu- 

 oles numerous and small in size; salt water. 



C. nutans S. (Fig. 163, d). About 150^* in diameter. 



Genus Oxnerella Dobell. Spherical; cytoplasm indistinctly 

 differentiated; eccentric nucleus with a large endosome; axial 

 filaments take their origin in the central granule; no contractile 

 vacuole; nuclear division typical mitosis (Fig. 55). 



0. maritima D. (Fig. 55). Small, 10-22iu in diameter; solitary, 

 floating or creeping; salt water. 



Family 3 Ciliophryidae Poche 

 Genus Ciliophrys Cienkowski. Spherical with extremely fine 



