50 PROTOZOA 



A. Pseudopodia the principal means of locomotion and feeding ; flagella 



absent or transitory . . . . .1. Sarcodina 



(1) Plastogamy only leading to an increase in size, never to the forma- 



tion of " fructifications." 



(«) Pseudopodia never freely coalescing into a network nor fine to 



the base ..... Rhizopoda. 



(*) Ectoplasm clear, free from granules ; pseudopodia, usually 



Ijlunt .... Ehizopoda Lobosa 



(**) Ectoj)lasm finely granular ; iiseudopodia slender, branching, 



but not forming a network, jiassing into the body by 



basal dilatation . . . Rhizopoda Filosa 



(h) Pseudopodia branching freely and coalescing to form networks ; 



ectoplasm granular ; test usually calcareous or sandy 



FORAMINIFERA 



(c) Pseudopodia fine to the very base ; radiating, rarely coalescing, 

 (i.) Pseudopodia with a central filament . Heltozoa 



(ii.) Pseudopodia without a central filament. 



(*) Body divided into a central and a periplieral jjart liy a 



" central capsule " . . . Radiolaria 



(**) Body without a central capsule . Proteomyxa 



(2) Cells aggregating or fusing into plasmodia V)efore forming a complex 



"fructification" ..... Mtcetozoa 



B. Cells usually moving by " euglenoid " wriggling or by excretion of a trail 



of vi.scid matter ; reproduction by alternating modes of brood-forma- 

 tion, rarely by Spencerian fission . . .II. Sporozoa 



C. Flagella (rarely numerous) the chief or only means of motion and 



feeding . . . . . III. Flagellata 



D. Cilia the chief organs of motion, in the young state at least ; nuclei 



of two kinds ..... IV. Infu.soria 



