body stripes in front of the mouth are twisted to the left. The anus
is terminal and the contractile vacuole may be terminal or situated
forwards in the dorsal region. The macronucleus is spherical and
has one micronucleus attached. Food consists mainly of bacteria.
Movement rapid, but interrupted.

Fresh and salt water, common in infusions.


Colpidium colpoda Ehr., sp. Fig. 38.

Synonyms: _Colpidium cucullus_ Kent '81; _C. striatus_ Stokes '85;
_Kolpoda cucullus_ Duj. '41; _Paramoecium colpoda_ Ehr. '38,
Quennerstedt '67; _Plagyiopyla nasula_ Kent '81, G. & R. '86;
_Glaucoma pyriformis_ G. & R. '86; _Tillina campyla_ Stokes '85, '88.

The body is oval, somewhat larger posteriorly, and a little
compressed dorso-ventrally. The anterior end is twisted a little from
the right to the left (more evident in fresh-water forms), and leans
somewhat toward the ventral side. Under this portion, on the ventral
side, lies the mouth in a large depression just above the middle of
the body. The entire body is covered with uniform and delicate cilia,
which are placed in longitudinal rows. These rows are almost straight
on the dorsal side, but bend on the ventral surface, following
the contour of the twisted anterior portion. The endoplasm is
finely granular; the oesophagus leading into it is very distinct.
Schewiakoff ('89) describes two membranes, an inner and an outer;
Maupas ('83) describes them as right and left. In the present species
I was able to make out only one. The macronucleus is central,
spherical in form, and bears a single minute micronucleus. The