wing in one direction.
The body is club-shape and moves with the swollen end in advance.
A comparatively small number of large granules are found in the
swollen portion, while the smaller posterior end is quite hyaline.
Contractile vacuole absent, and a nucleus was not seen. Frequent in
decomposing vegetable matter. Length 37 mu. Traverses a distance of
160 mu in one minute.

The fresh-water form of _A. guttula_ has a vacuole, otherwise
Dujardin's description agrees perfectly with the Woods Hole forms.

[Illustration: Fig. 1.--_Amoeba guttala_.]

Amoeba? Fig. 2.

A more sluggish form than the preceding, distinguished by its larger
size, its dense granulation, and by short, rounded pseudopodia,
which, as in _Amoeba proteus_, may come from any part of the body.
A delicate layer of ectoplasm surrounds the granular endoplasm, and
pseudopodia formation is eruptive, beginning with the accumulation
of ectoplasm. Movement rapid, usually in one direction, but may be
backwards or sideways, etc. Contractile vacuole absent; the nucleus
is spherical and contains many large chromatin granules. Length 80 mu;
diameter 56 mu.

[Illustration: Fig. 2.--_Amoeba_ sp.]

Genus TRICHOSPHAERIUM Schneider '78

Synonym: _Pachymyxa hystrix_ Gruber.

Marine rhizopods, globular or irregular in form, and slow to change
shape. Dimorphic. Both forms multinucleate during vegetative life.
Pseudopodia are long, thin, and thread-form, with rounded ends.
Their function is neither food-getting nor locomotion, but probably
tasting. The plasm of both forms is inclosed in a soft gelatinous
membrane. In one form the jelly is impregnated with needles of
magnesium carbonate (Schaudinn), but these are absent in the other
form. The membrane is perforated by clearly defined and permanent
holes for the exit of the pseudopodia. Reproduction occurs by
division, by budding or by fragmentation, but the parts are
invariably multinucleate. At the end of vegetative life the
needle-bearing form fragments into numerous mononucleate parts; these
develop into adults similar to the parent, but without the spines.
At the end of its vegetative life this new individual fragments into
biflagellated swarm-spores which may conjugate, reproducing the form
with needles. Size up to 2 mm.

Trichosphaerium sieboldi Schneider. Fig. 3.

With the characters of the genus. A form which I have taken to be a
young stage of this interesting rhizopod is described as follow