HELIOZOA 



247 



Without skeleton; no jelly mantle Suborder 1 Aphrothoraca 



With gelatinous mantle; no silicious spicules Suborder 2 Chlamydophora 



With isolated or united spicules Suborder 3 Chalarothoraca 



Skeleton glubular, silicious with many apertures. . .Suborder 4 Desmothoraca 



Suborder 1 Aphrothoraca Hertwig 



Without envelope or skeleton in the active stage; envelope 

 in encysted stage. 



Fig. 98 a. Actinophrys sol. X265. 



b. Actinosphaerium eichhorni. X30. 



c. Camptonema nutans. X230 (After Schaudinn). 



Genus Actinophrys Ehrenberg. Spherical with a smooth 

 membranous envelope; cytoplasm vacuolated, especially ecto- 

 plasm. With symbiotic Zoochlorellae. A central nucleus; one 

 large contractile vacuole. Axopodia straight, numerous, axial 

 filament arising from the surface of the nucleus. "Sun animal- 

 cules." Several species. 



Actinophrys sol Ehrenberg (Fig. 98, a). Spherical. Ecto- 

 plasm contains numerous large vacuoles; endoplasm granulated 

 with numerous small vacuoles. A large central nucleus. Solitary 

 but may be colonial when young. Body diameter 40 to 50 

 microns. Among plants in still fresh water. 



Genus Actinosphaerium Stein. Spherical. Ectoplasm con- 

 sists almost entirely of large vacuoles in one or several layers; 

 endoplasm with numerous small vacuoles. Numerous nuclei. 

 Axial filaments of the pseudopodia end in the ectoplasm. Two 

 species. 



Actinosphaerium eichhorni Ehrenberg (Fig. 98, h). Numer- 

 ous nuclei scattered in the peripheral portion of the endoplasm. 



