CLASS RHIZOPODA. 



OEDEK I. PKOTOPLASTA. 



Nearly all the fresh-water Rhizopods belong to this 

 order. They are either naked or covered with a chitin- 

 oid or siliceous shell, and move by the aid of pseudo- 

 podal projections of the sarcode body. 



ORDER II. IIELIOZOA. 



Body spherical, with many vacuoles or clear globules 

 which give it a foamy appearance ; usually a single nu- 

 cleus, but sometimes several, and distinct contractile ves- 

 icles. Pseudopodia delicate, granular, emanating from 

 all parts of the body, commonly simple and tapering, 

 rarely forked or anastomosing, usually straight but highly 

 flexible and contractile. 



ORDER III. RADIOLARIA. 

 Marine. Skeleton siliceous. 



ORDER IV. FORAMINIFERA. 



Mostly marine. Shell usually calcareous. 



ORDER V. MOKERA. 



Without organs, body free and naked, composed of 

 structureless sarcode. 



