Synonym: _Metra radiosa_ Quenn.

The body is elongate, slightly narrowed anteriorly, and drawn out
posteriorly into a long, retractile, tail-like portion. Five large
cirri extend outward from the anterior extremity. The caudal portion
may be extended to a distance equal to twice the length of the body
or contracted to half the length. The peculiar nervousness of this
form made it extremely difficult to study, and the oral region was
imperfectly made out. The anterior cirri appear to line the upper
left border of the peristome, which is marked by a row of large
cilia. The peristome begins upon the right side of the anterior end
and passes backward and to the left, narrowing at this point. The
mouth is very small and difficult to see. It is apt to stay in
one locality under zoogloea, switching back and forth with great
vivacity, or hanging on by the posterior cilia while the anterior
end stretches out in the surrounding medium. Nucleus and contractile
vacuole were not observed. Length 45µ.


[Illustration: Fig. 50.--_Epiclintes radiosa_.]


Genus AMPHISIA Sterki '78.

(Sterki '78; Kent '81; Bütschli '88.)

The body is plastic and soft, colorless or slightly tinged with
yellow or red. In form it is oval or elongate, the posterior end
is rounded and slightly reduced in diameter, but does not form a
distinct tail. The anterior end is also rounded and similarly reduced