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