Chap. III.] 



GROUPS OF PROTOZOA. 



27 



I. Rhizopoda; example: Amoeba, Gromia, Nummu- 



lites. 



II. Heliozoa ; example : Actinophrys (Sun animal- 

 cule). 

 III. Radiolaria ; example : Acanthometra, Chilomma. 



Fig. 2 B. Actinophrys sol, showing the yacuolated ectosarc, the finely 

 granulated endosarc, the nucleus, contractile vacuole. and pseu- 

 dopodial filaments. (After Leidy.) 



Leaving out of our consideration those simple and 

 incompletely known forms in which no nucleus is 

 developed in the protoplasm (Wlonera),* we may dis- 

 tinguish the naked Amoeba-like Rhizopoda from those 



* It is possible that in such forms the nuclear substance is 

 diffused through the protoplasm (Gruber). 



