CHAPTEE III 



PROTOZOA {COXTIXUEL) : SAKCODINA 



I. Sarcodina. 



Protozoa performing most of their life-processes hj pseudopodia ; 

 nucleus frequently giving off fragments (chromidia) which may 

 play a part in nuclear reconstitution on division ; sometimes with 

 brood-cells, which may be at first flagellate ; but never reproducing 

 in the flagellate state} 



1. Ehizopoda 



Sarcodina of simple form, whose pseudopodia never coalesce into 

 networks (1),^ nor contain an axial filament (2), which commonly 

 multiply by binary fission (3), though a brood-forwMtion may 

 occur ; which may temporarily aggregate, or undergo temporary or 

 permanent plastogamic union, but never to form large plasmodia 

 or complex fructifications as a prelude to spore-formation (4) ; test 

 when present gelatinous, chitinous, sandy, or siliceous, simple and 

 1-chambered (5). 



Classification.^ 



I. Ectoplasm distinct, clear ; pseudopodia blunt or tapering, but not brandl- 

 ing at the apex ...... Lobosa 



Amoeba, Auctt. ; Pelomyxa, Greeff ; Trichosphaerium, A. Schneid. ; 

 Dinamoeha, Leidy; Amphizonella, GreeS • Gentropyxis, Stein; Arcella, 



' On this ground I have referred Faramoeba, Greeff, to the Cryptomonadineae. 



^ Differences (1) from Foraminifera ; (2) from Heliozoa ; (3) from Proteomyxa 

 and Sporozoa ; (4) from Myxomycetes ; (5) from many Foraminifera. 



^ I have not followed the usual olas.sification into Gymnamoebaeand Thecamoebae, 

 according to the absence or presence of a test (perforated by one or more openings) 

 in the active state, as such a test occurs in isolated genera of Flagellata and 

 Infusoria, and does not appear to have any great systematic importance. 



SI 



