placed except
around the proboscis. The endoplasm is thickly packed with large
granules (food particles) in the anterior half and with finely
granular particles in the posterior half. The elongate macronucleus
lies a little above the center among the larger granules; the
contractile vacuole is double, one on each side of the median line
and at the posterior end of the body among the finer granules. The
anus is posterior. Length 90 mu to 160 mu; greatest width assumed 65 mu.
When fully expanded the posterior end assumes a curious polyhedral
form. (Fig. 28 b.)

This form differs slightly from others of the same species as
described by different observers, the most striking difference being
the presence of two contractile vacuoles in place of the usual one.
These are very slow to fill and grow to a large size before diastole.
The membrane is very tough and retains its form easily under pressure
of the cover glass. Another characteristic feature is the flattening
of the surfaces between the striae. Decaying algae.

[Illustration: Fig. 28.--_Lacrymaria lagenula_.]

Lacrymaria coronata Cl. & Lach. '58. Fig. 29.

Synonyms: _L. lagenula_ Cohn '66; Moebius '88; _L. cohnii_ ? Kent '81;
_L. versatilis_ Quen. '67.

Form flask-like and similar to _L. lagenula_, contractile but tough.
The contractile vacuole is terminal, the proboscis is short, slightly
raised and separated from the body by a deep cleft; the buccal cilia
are inserted part way up on the proboscis. Form changeable, from
short, sac-like to elongate and vermiform. Length 85 mu.

This species is not very different from _L. lagenula_, but I noted
that in addition to the elongate nucleus, the body striae are much
more apparent here and seem to sink into the cuticle, giving the
periphery, especially at the collar region, a curious crenulated
effect. The endoplasm is very densely granular and colored a
blue-green, probably from food particles. The number of striae is much
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; Buetschli '88; Schewiakoff '89; Shevyakov '96.)

The only well-known representative is very elongate, large (up
to 3 mm. Van Ben