IV. SPOROZOA: SUMMARY OF IMPORTANT FACTS. 219 



the Protozoa into the classes Rhizopoda, Flagellata, Ciliata, and 

 Sporozoa. 



8. The RHIZOPODA have changeable protoplasmic processes, 

 the pseudopodia. 



9. The Rhizopoda are subdivided into Monera, Lobosa, Helio- 

 zoa, Radiolaria, Foraminifera, and Mycetozoa. 



10. The Lobosa and Monera have no definite shape. The 

 Lobosa have a nucleus, the Monera are anucleate. 



11. Heliozoa and Radiolaria are spherical and have fine radiat- 

 ing pseudopodia and frequently silicious skeletons. They are dis- 

 tinguished by the occurrence of a central capsule in the Radiolaria 

 which is lacking in the Heliozoa. 



12. The Thalamophora (Foraminifera) have a shell, closed at 

 one end, at the other with opening for the extension of pseudopodia. 

 The shell is chitinous or calcareous, one or several chambered, 

 straight or spiral, sometimes with close walls, sometimes perforated 

 with pores; the pseudopodia are occasionally lobular, but usually 

 filiform, branching and anastomosing. 



13. The Foraminifera are of great geological importance on 

 account of their numbers and their shells, which have built and 

 are still building extensive beds of rock (chalk, nummulitic lime- 

 stone). The silicious skeletons of the Radiolaria are less important. 



14. Mycetozoa (Myxomycetes of botanists) are mostly enormous 

 Amoebae with branched reticulate protoplasm (plasmodium). They 

 form complex reproductive structures (sporangia, etc.), recalling 

 those of the fungi. 



15. FLAGELLATA have one or a few long vibratile processes 

 flagella which serve for locomotion and for the taking of food. 



16. The Autoflagellata have only flagella; they feed like plants 

 (Volvocina) by means of chlorophyl, or have a mouth for the tak- 

 ing of food, or a collar (Choanoflagellata). 



17. The Dinoflagellata have two kinds of flagella and usually 

 an armor of cellulose. 



18. The Cystoflagellata have a gelatinous body enclosed in a 

 firm membrane (Noctiluca). 



19. The CILIATA (INFUSORIA in the narrower sense) have 

 numerous slender vibrating processes, the cilia, a cuticle, and hence 

 fixed openings for the ingestion of food (cytostome) and for extru- 

 sion of indigestible matter (cytopyge). 



21. Of great interest is the occurrence of two kinds of nuclei, 

 a functional nucleus (macronucleus) and a sexual nucleus (micro- 

 nucleus, paranucleus). 



