outline. The anterior end is bent distinctly to the left and forms a
characteristic process, which, together with the entire margin of the
body, is soft and flexible. The posterior end is, as a rule, broadly
rounded. The ventral surface is finely striate, and this surface
alone is ciliated. The lines of cilia converge at the mouth, and at
this region the cilia are somewhat larger and more distinct, thus
forming a functional adoral zone. The mouth is median and is situated
in the anterior half of the body. It is surrounded by a well-defined
armature, composed usually of from 10 to 16 rods. The contractile
vacuoles are quite varied and from one to many in number, the
number increasing with the size of the individual. The macronucleus
is usually single, elliptical in form, and centrally placed;
one micronucleus. Reddish granular pigment and trichocysts are
occasionally present.


Chilodon cucullulus Müll., sp. Fig. 35.

Synonyms; _Colpoda cucullus_ O. F. Müller; _Loxodes cucullulus_;
_Chilodon uncinatus_ Ehr. '58, Perty '52, Dujardin '41; _L. dentatus_
Duj., etc.

This extremely variable form has received so many different names
that it hardly pays to enumerate them. It is one of the commonest
and most widely spread ciliates known, although at Woods Hole I was
surprised to see it so rarely. It is the type species of the genus
and needs no further description. The specimens observed at Woods
Hole had numerous contractile vacuoles and were 42 to 45µ long and
from 28 to 32µ wide.