Genus LIONOTUS Wrzesniowski '70.

(Incorrectly called _Litonotus_ by many. Entz '84; Gruber '84;
Bütschli '88; Kent '81; Schewiakoff '89; Shevyakov '96.)

The body is elongate and somewhat lance-shaped, widest at the central
part and tapering to a point at the anterior end. The posterior end
may be similarly tapered or rounded. The anterior end frequently
proboscis-like, flat, and flexible, while the entire body is more or
less elastic and contractile. The right side is flattened and alone
provided with cilia, while the left side of the body proper is
arched; on the left side of the proboscis is a row of coarse cilia
resembling an adoral zone, and a row of trichocysts. A long peristome
stretches down the thin, ventral side of the proboscis, and the mouth
proper is situated at the junction of the proboscis and body; the
mouth, as a rule, is invisible. The ciliated right side alone is
striated in the majority of species. The contractile vacuole may be
single or multiple, usually in the posterior region of the body and
dorsal in position. The macronucleus is usually double, rarely single
or quadruple, but may occasionally break into numerous smaller
pieces. Movement, free-swimming or gliding, with especial tendency
to get under clumps of foreign matter.

Fresh and salt water.


Lionotus fasciola Ehr. Fig. 33.