ed. The shell is quite thick.
The animal moves through the water very slowly. Dark brown in color.
Length 48 mu; width 44 mu.

[Illustration: Fig. 18.--_Exuviaella lima_.]

Exuviaella marina Cienkowsky. Fig. 19.

A smaller form than the preceding, more elliptical in outline, with
a thinner shell and with large granules throughout the endoplasm.
The nucleus is spherical and subcentral in position and possesses a
distinct central granule. This may be a small variety of _E. lima_.

[Illustration: Fig. 19.--_Exuviaella marina_.]

Genus GYMNODINIUM Stein '78.

(Bergh '81; Kent '81; Pouchet '83, '85; Entz '84; Schuett '95.)

The general structure of these forms is similar to that of
_Glenodinium_; the most striking and positive difference is the
absence of a shell. The animals are, as a rule, spherical, yet they
may be pointed at the two ends or at one of them. They are also
frequently flattened dorso-ventrally. The transverse furrow may
be either circular and straight around the body or may describe a
spiral course, passing even twice around the body. The flagella
arise near cross-furrow or, in some cases, in longitudinal furrow.
Chromatophores may or may not be present and food-taking is holozoic,
in many cases at least. In some cases ectoplasm and endoplasm can be
distinguished. Fresh and salt water.

Gymnodinium gracile Bergh '82, var. sphaerica, n. Fig. 20.

The body is divided by the transverse furrow into a shorter anterior
and a longer posterior part. The longitudinal furrow is broader at
the posterior extremity than at the cross-furrow. The structural
feature upon which this new variety is made is the unvarying
plumpness of the body, making it almost spherical, except for
a slight flattening dorso-ventrally. The nucleus is large and
ellipsoidal, with characteristic longitudinal markings of chromatin.
The endoplasm is evenly granular, with a number of large ingested
food bodies. The color is brown, not rose-red as in Bergh's species,
nor is the Woods Hole form as large as the latter. Length of body
68 mu; width 55 mu. Common.

[Illustration: Fig. 20.--_Gymnodinium gracile_, var. _sphaerica_.]

Genus GLENODINIUM (Ehr.), Stein '83.

(Bergh '82; Buetschli '86; Pouchet '85; Daday '86.)

Small globular forms with two distinct furrows, one transverse around
the body, the other longitudinal upon the face only. The shell is
soft and structureless with a distinct aperture near the meeting
point