nor hyaline caudal region,
and the contractile vacuole is double or multiple on the dorsal side
near the posterior end. Cilia are present only on the under (right)
side, with, however, a row of large cilia marking the course of the
elongate mouth, upon its left side. The right side is striated, the
left arched and without markings. The endoplasm is finely granular
with, however, larger food particles in the process of digestion,
while specimens are occasionally seen with the natural form
completely lost through distortion caused by over-large captures (Cf.
also Wrzesniowski '70, p. XXIII, fig. 32). Movement continuous, slow,
and gliding; very little tendency to jerking movements. Macronucleus
double, both parts spherical, and placed in about the center of the
larger part of the body; closely approximated but not, as Schewiakoff
described, connected. In conjugation, a large form unites with a
smaller one, the mouth parts being connected. Details of conjugation
and macronuclei not made out. Length 200 mu to 600 mu.

[Illustration: Fig. 33.--_Lionotus fasciola_.]

KEY TO MARINE GENERA OF CHLAMYDODONTIDAE.

Diagnostic characters: Form usually ellipsoid, never very elongate.
Transverse section of body circular or elliptical. The mouth is
usually some distance from the anterior end and may be in the
posterior part. Sometimes it is in the center of the ventral
surface, again on the right side. The oesophagus invariably has
a well-developed buccal armature, or a smooth peculiarly built
oesophageal tube. Food particles of large size.

1. Body cylindrical. Cilia about Genus *_Nassula_
entire body

Body flat 2

2. a. Without a caudal process 3

b. With a caudal process 5

3. a. Anterior end angular 4
on left side

b. Anterior end rounded Genus _Chlamydodon_

4. a. Dorsal striae and cilia present, Genus _Orthodon_
ventral cilia longer

b. Dorsal striae and cilia absent; Genus *_Chilodon_
posterior end not pointed

c. Dorsal striae and cilia absent; Genus _Scaphidiodon_
posterior end pointed

5. a. Caudal spine with posterior 6
bristle-like cilia

b. Caudal spine without posterior Genus _Trochilia_
bristle-like cilia;
ventral cilia reduced

6. a. With pigment spot on anterior Genus _AEgyria_
angle

b. Without su