Lacrymaria lagenula Clap. & Lach.  Fig. 28, a, b.

Synonym:  L. tenuicula Fromentel ’74.

Body more or less flask-shape, two or three times as long as broad, with conical apex, which is slightly elastic and protrusible; surface obliquely striate, with well-defined lines, 14 to 16 in number; cilia uniform on the body, with a crown of longer ones at the base of the conical proboscis.  The body cilia are not thickly 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 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.