22. Shell with a short neck 



Cucurhitella Penard 

 Shell with a long neck 



Ponugulasia Rhumbler 



23. Plates squarish 



^uadrulella Cockerell 

 {^uadruh Schuhe) 

 Plates rounded or irregular 24. 



24. Shell pear-shaped; animal not brightly colored 



'Hehela Leidy 

 Shell spherical or ovoid; animal green, yellow or red 

 Heleopera Leidy 



25. With several thickened tentacles used for food-gathering but not for 



locomotion — Suctoria 26. 



With a few long or many short, flexible or vibratile, hair-like processes 



(shown by the movement of the surrounding water, even when they 



are not visible) 31. 



26. Tentacles much branched, flexible but not contractile 



Dendrocometes Stein 

 Tentacles contractile, not branched 27. 



27. Body with a semi-transparent sheath or lorica, which is usually sac-like, 



cubical or triangular 28. 



No lorica; animal colonial, plant-like, or else almost spherical, with or 



without a stalk 29. 



28. Lorica cubical, sac-like 



Solenophrya Claparede & Lachmann 

 Lorica an inverted triangle, with a short stalk; tentacles extending from 

 the two upper corners 



Aaneta Ehrenberg 



29. A colonial, plant-like form, with tentacles at the ends of the branches 



Dendrosoma Ehrenberg 

 Animal almost spherical, with or without a stalk 30. 



30. At the end of a thin stalk 



Podophrya Ehrenberg 

 No stalk 



Sphaerophrya Claparede & Lachmann 



31. With a few (usually one to ten) long, vibratile, hair-like structures 



(flagella), often difficult to see but indicated by the water currents; 

 in colonial forms, each individual of the colony may have one or more 

 flagella — Flagellates 32. 



With many, short, vibratile, hair-like structures (cilia) over or around 

 the body — Ciliates 55. 



32. Body colored wholly or in part; chromatophores (color bodies) usually 



present (usually brown, yellow or green) 33. 



Body not colored or only slightly brownish 46. 



39 



