http://en.wikipedia.org/wiki/Peritrich
The larger order of peritrichia are the Sessilida. Most of these have modified posterior kinetosomes which secrete a contractile stalk. The unattached stage, called a telotroch, is mouthless. These are common in both freshwater and marine environments, and many live attached to aquatic plants and animals. They are either solitary or produce branched colonies. A few secrete alorica. Vorticella is one of the best-known genera. Stalks may be as long as 2 mm, and in some cases where they are highly contractile can be extended up to 3 mm.
The larger order of peritrichia are the Sessilida. Most of these have modified posterior kinetosomes which secrete a contractile stalk. The unattached stage, called a telotroch, is mouthless. These are common in both freshwater and marine environments, and many live attached to aquatic plants and animals. They are either solitary or produce branched colonies. A few secrete alorica. Vorticella is one of the best-known genera. Stalks may be as long as 2 mm, and in some cases where they are highly contractile can be extended up to 3 mm.
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