PHYLUM PROTOZOA. ONE-CELLED ANIMALS 



41 



pseudopodia. Mostly marine. 

 Ex. Globigerina bulloides (Fig. 

 17). 

 Subclass 2. Actinopoda (Gr. aktis, ray; 

 pous, foot). Typically floating 

 forms with radiating, un- 

 branched pseudopodia, each 

 with central filament. 



Order 1. Heliozoa (Gr. helios, sun; 

 zoion, animal). Pseudopodia 

 are thin, radially arranged, and 

 usually supported by axial 

 threads; spherical; chiefly in 

 fresh water. Ex. Actinophrys sol 

 (Fig. 17). 



Order 2. Radiolaria (L. radiolus, a little 

 ray). Marine. Often spherical; 

 pseudopodia raylike; protoplasm 

 divided into inner and outer 

 parts by a perforated capsule; 

 usually a skeleton of silica or 

 strontium sulfate. Ex. Acan- 

 thometron elasticum (Fig. 40). 



Subclass 3. Mycetozoa (L. mykes, fungus; 

 zoion, animal). Slime animals. 

 Adult phase consists of a sheet 

 of multinucleate protoplasm up 

 to several inches in width. They 

 are found on decaying organic 

 matter, such as rotting leaves 

 and wood. The mycetozoa pro- 

 duce resistant spores that sur- 

 vive dry conditions. 



SELECTED COLLATERAL 

 READINGS 



Calkins, G.N. The Biology of the Protozoa, 

 Lea & Febiger, Philadelphia, 1933. 



Cushman, J. A. Foraminifera, Their Classifica- 

 tion and Economic Use. Har\'ard Univ. 

 Press, Cambridge, 1948. 



Hagelstein, R. The Mycetozoa of North Amer- 

 ica. Published by author, Mineola, N.Y., 

 1944. 



