Genus *_Epiclintes_
without short lateral bristles

Anal cirri absent; no bristles Genus _Uroleptus_

5. With frontal cirri 6

No frontal cirri; 2 to 3 rows of Genus _Holosticha_
ventral cirri; anal cirri small

6. Right margin of peristome straight Genus _Oxytricha_
as far as the anterior end; 5 rows
ventral cirri; 5 anal cirri

Right margin of peristome curved 7

7. Five rows or less of ventral cirri 8

More than 5 rows of ventral cirri Genus _Urostyla_

8. Membranelles normal; 5-10 anal Genus *_Amphisia_
cirri; no caudal cirri

Membranelles normal; 5 to 10 anal Genus _Stylonychia_
cirri; 3 caudal cirri

Membranelles very large and Genus _Actinotricha_
powerful; adoral zone not
continued to mouth; 5 anal cirri

* Presence at Woods Hole indicated by asterisk.

Genus EPICLINTES Stein '62.

(Stein '62, '64, '67; Mereschowsky '79; Gruber '87; Buetschli '88.)

Very active, contractile, colorless forms of rather small size. In
the fully expanded condition the body is oval and long, with its
greatest width in the center or at the front half of the body. The
posterior end is always drawn out into a relatively long tail, which
is extremely elastic. The peristome is short and stretches around the
front end of the animal. In the frontal region are from one to three
rows of cirri. The ventral surface is covered with longitudinal rows
of cilia, the number of rows being in dispute (6 to 7 according to
Stein; 9 according to Mereschowsky and Rees) Some of these cilia
project from the lateral edges and from the posterior end, where
they are slightly elongated. The anus is dorsal and placed at the
beginning of the posterior process. Macronucleus probably double.
Movement is rapid and restless, the tail process contracting to jerk
the body backward. Salt water.

Epiclintes radiosa Quenn. Fig. 50.

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