Fresh and salt water. Length 45µ; diameter 25µ.


[Illustration: Fig. 52.--_Euplotes charon_, dorsal and ventral
aspects.]


Euplotes harpa Stein. Fig. 53.

The body is elongate, oval, somewhat widened anteriorly, and has
rounded ends. The frontal margin is three-toothed. Ten ventral cirri.
Dorsal surface provided with 8 longitudinal markings. The peristome
is long and broad, with considerable variation. The adoral zone
consists of powerful membranelles arranged in a continuous curve
from the mouth to the extreme right frontal margin. Seven of the 10
ventral cirri are situated at the anterior extremity; the remainder
are arranged in a triangle on the right edge. The anal cirri, 5 in
number, are long and stiff; the marginal cirri smaller and finer. The
nucleus and contractile vacuole are similar to those of the preceding
species.

Length 95µ; width 54µ.


[Illustration: Fig. 53.--_Euplotes harpa_.]


Genus DIOPHRYS Dujardin '41.

(Bütschli '88.)