Common genera - — - Epistylis "Vaginicola 



Vorticdla Cothurnia 



Carchesium Trichodirm 



Zoothamnium Platycola 

 Class SUCTORIA 



Mature animals with no locomotor structures; with suctorial and with 

 piercing tentacles 



Common genera — Dendrosoma Sphaerophrya 



Dendrocometes Acxneta 



Podophrya Solenophrya 



KEY TO THE COMMON GENERA OF PROTOZOA 



1. Body with no fixed form or covered by a thin shell, moving with a slow, 



flowing motion rather than a rapid, swimming motion; hair'like struC' 

 tures, if present, in the form of stiff, ray-like projections — Rhizopods 2. 

 Body with a fixed although often a very flexible form, usually swimming 

 rapidly by means of a few long or many short, flexible or vibratile, 

 hair-like structures, but sometimes attached or with tentacles 25. 



2. Body not surrounded by a definite shell 3. 

 Body almost or entirely surrounded by a shell 9. 



3. Animal moving by means of broad or finger-like protoplasmic extensions 



or pseudopodia 4. 



Animal with hair-like rays 6. 



4. Body orange or red; pseudopodia often anastomosing; with fine, pin- 



shaped rays, which are often unobserved 

 Vampyrella Cienkowski 

 Body almost colorless; no hair-like rays 5. 



5. With a few very broad pseudopodia from one side of the body; containing 



many nuclei and symbiotic bacteria; found in sphagnum bogs 



Pelomyxa Greeif 

 With many finger-like pseudopodia over body; seldom more than one 

 nucleus; no symbiotic bacteria 



Amoeba Ehrenberg 



(Chaos Linn.) 



6. Body orange or red; with pin-like rays and with broad pseudopodia 



Vampyrella Cienkowski 

 Body almost colorless; with long spines or with long ray-like pseudopodia, 

 or both 7. 



7. With an external envelope with long spiny rays, some of which are forked 



at the end, in addition to hair-like pseudopodia 

 AcanthocysUs Carter 

 No external envelope with spiny rays; with long, hair-like, unforked 

 pseudopodia 



36 



