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." 



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



the base ..... Rhizopoda. 



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



blunt .... Rhizopoda Lobosa 



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



but not forming a network, passing into the body by 



basal dilatation . . . Rhizopoda Filosa 



(6) 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 complex 



" 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 



