larger than in the preceding species. The membrane is very tough and
retains the shape of the body, even with the full pressure of the
cover glass. Micronucleus and trichocysts were not observed.


[Illustration: Fig. 29.--_Lacrymaria coronata_.]


Genus TRACHELOCERCA (Ehr. '83) Cohn '66.

(Quennerstedt '67; Gruber '87; Entz '84; Kent '81; Gourret & Roeser
'88; Bütschli '88; Schewiakoff '89; Shevyakov '96.)

The only well-known representative is very elongate, large (up
to 3 mm. Van Beneden), and very contractile. The main feature of
importance in distinguishing it is the 4-part structure of the mouth
region, which, however, may not be obvious. Pharynx faint and smooth.
Contractile vacuole terminal. Macronucleus in one central body or in
numerous pieces scattered throughout the cell. Salt water.


Trachelocerca phoenicopterus Cohn '66. Fig. 30.

Synonyms: _T. sagitta_ Ehr. '40, Stein '59; _T. tenuicollis_
Quennerstedt '67, Kent '81; _T. minor_ Gruber '87, Shevyakov '96.

The body is extremely elongate and ribbon-like, and this, combined
with its wonderful power of extension and retraction, makes it one of
the most curious and interesting of microscopic forms. The anterior
end is square or cylindrical; the type species has a four-sided