PKOTOPLASTA 



Order I.--Protoplasta. 



The Protoplasta include nearly all fresh-water forms 

 except the Heliozoa. Naked or provided with an exterior 

 chitinoid, or siliceous shell. There are two sub-orders. 



Sub-Order I. Lobosa. Pseudopods are lobose projec- 

 tions from the clear ectosarc, simple, often more or less 

 ramose, but never anastomosing, blunt or pointed. 



Endosarc granular, not distinctly differentiated from 

 the ectosarc, containing large, colorless or yellowish, some- 

 times bright green, spherical corpuscles, and one or more 

 nuclei, and contractile vesicles. Reproduction by division. 



Under certain conditions some of them become en- 

 cysted, and the contents of the cysts may subdivide, or 

 the nucleus may break up into what are apparently 

 spermatozoids, and the endosarc into nucleated cells like 

 ova. 



The distinguishing characteristic of the Lobosa is the 

 coarse, digitate form of the pseudopodia. In the Filosa 

 the pseudopodia are usually much finer, and in the order 

 Heliozoa they are like long rays, radiating from the 

 centre of the spherical body of the animal. 



