50 PROTOZOA 



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



absent or transitory . . . . . I. Sarcodina 



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



tion of " fructifications." 



(a) Psendopodia never freely coalescing into a network nor fine to 



the base ..... Rhizopoda. 



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

 blunt .... Rhizopoda Lobosa 



(**) Ectojolasm finely granular ; pseudopodia slender, branching, 

 but not forming a network, passing into the body by 

 basal dilatation . . . Rhizopoda Filosa 



(b) 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 . Heliozoa 

 (ii.) Pseudopodia without a central filament. 



(*) Body divided into a central and a peripheral part by a 



" central capsule " . . . Radiolaria 



(**) Body without a central capsule . Proteomyxa 



(2) Cells aggregating or fusing into plasmodia before forming a comple: 



"fructification" ..... Mycetozoa 



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



of viscid 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. Infusoria 



[A 



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