Marine Protozoa from Woods Hole | Page 5

2 no mouth
With pharynx and distinct mouth Family Peranemidæ
2. Body plastic; usually with Family Euglenidæ chromatophores and
eye-spot
Body plastic; no chromatophores; Family Astastidæ no eye-spot
Family Euglenidæ:
Body Euglena-like, inclosed Genus Trachelomonas in shell with round
opening for exit of flagellum
Family Astastidæ:
Body with one flagellum Genus *Astasia
Family Peranemidæ:
1. Body striped; plastic; Genus Heteronema two diverse flagella
2. Body striped; not plastic; Genus *Anisonema posterior flagellum
longer than the other
3. Body striped; not plastic; Genus Entosiphon with rod-like organ in
pharynx
* Presence at Woods Hole indicated by asterisk.
Genus MASTIGAMOEBA F. E. Schultze '75.
(Kent '81; Bütschli '86; Klebs '92; Senn 1900.)
In general the form is oval and either regular in outline or irregular

through the presence of many pseudopodia. One flagellum usually
quite large and distinct. Differentiation of ectoplasm and endoplasm
distinct or wanting. One to several contractile vacuoles. The
pseudopodia are occasionally withdrawn, and the flagellum is the sole
means of locomotion. In some cases the flagellum turns into a
pseudopodium, and, conversely, the pseudopodium at one end may
become a flagellum (see below). In some rare cases the ectoplasm
secretes a gelatinous mantle. Reproduction not observed.
Fresh and salt water.
Mastigamoeba simplex, n. sp. Fig. 7.
A very small form, first seen in the flagellated stage, aroused my
interest by reason of the fact that its flagellum lost its regular outline
and became amoeboid, turning to a pseudopodium, while at the same
time other pseudopodia were protruded from different parts of the
periphery. In this condition ectoplasm and endoplasm could be made
out with the clearest definition. After the pseudopodia were well
formed, the body became flat and closely attached to the glass slide. In
a short time one of the pseudopodia became longer than the rest; the
body became more swollen; the pseudopodia were gradually drawn in,
with the exception of the more elongate one; this became active in
movement and finer in diameter, until ultimately it formed a single
flagellum at the anterior of a small monadiform flagellate. The process
was repeated two or three times under my observation, so that I am
convinced that it was not a developmental form of some rhizopod.
Several of them were seen at different times during the summer, and
they were always of the same size and form in the flagellated or
amoeboid condition. I did not make out their reproduction, and I shall
not be satisfied that this is a good species until their life history is
known.
In decaying algæ. Length 10µ.
[Illustration: Fig. 7.--Mastigamoeba simplex.]
Genus CODONOECA James Clark '66.

(Kent '81.)
Small forms inclosed in cup or "house" of ovoid or goblet shape,
colorless and probably gelatinous (chitin?) in texture, and borne upon a
stalk. The monad does not completely fill the test. Contractile vacuole
single, posterior.
Codonoeca gracilis, n. sp. Fig. 8.
The cup is urn-shaped with a well-defined neck or collar borne upon a
shoulder-like end of the body. It is hyaline, colorless, and carried upon
a stalk equal in length to the cup or shorter than this. The animal does
not fill the cup, nor is it attached by a filament to the latter. There is a
single flagellum. The nucleus is minute and lateral in position; the
contractile vacuole is in the posterior end of the body. Total length of
cup and stalk 21µ; of cup alone 12µ. This minute form looked so much
like a choanoflagellate that I supposed it to be one until I discovered an
empty case (Fig. 8).
[Illustration: Fig. 8.--Codonoecea gracilis.]

Genus MONAS (Ehr.) Stein '78
(Kent '81; Bütschli '86; Klebs '97; Senn 1900.)
The body is small, globular or oval and either free-swimming or
fastened by one of the two flagella. The body is sometimes a little
amoeboid, with short pseudopodial processes. In addition to the main
flagellum, there are usually one or two small flagella at the basis of the
larger one. The nucleus is usually anterior, and one or two contractile
vacuoles are present.
Monas sp. Fig. 9.
An extremely small form (3µ) attached by a thread of
protoplasm--perhaps a flagellum, to algæ. The body is ovoid and the
main flagellum is about four times the length of the body. The

contractile vacuole is posterior. Only one specimen was seen and upon
this I shall not attempt to name the species.
[Illustration: Fig. 9.--Monas sp.]
Genus MONOSIGA Kent '81.
(Bütschli '86; Francé '97; Senn 1900.)
Small colorless forms of Choanoflagellida, always naked and solitary.
The posterior end is attached directly to the substratum, or there is a
short stalk not exceeding the body in length. Kent '81 distinguished
nine species, but Bütschli questioned the accuracy of many of these,
and in this he was followed by Francé '97, who recognized three
species--Monosiga ovata, M. fusiformis,