nnulate. Length of cup 70 mu to 80 mu. The stalk which
supports the cup is extremely variable in length. The animal is borne
upon a stalk of variable length within the cup.

Entz states that the many variations which this species exhibits run
into each other so gradually that he does not believe it wise to
separate them. The Woods Hole forms which I found on algae of various
kinds were nearly of a size, and did not vary much from the one
figured. Kellicott '94 described a _Cothurnia_ from Woods Hole under
the name of _C. longipes_, which I believe is only a long-stemmed
variety of _C. nodosa_. My form has the following dimensions: Cup
75 mu; cup stalk 38 mu; animal stalk 14 mu.

[Illustration: Fig. 64.--_Cothurnia nodosa_.]

KEY TO FAMILIES OF SUCTORIA.

a. Unattached forms; ventral cilia _Hypocomidae_
present; one suctorial tentacle

b. Attached forms; thecate and _Urnulidae_
athecate tentacles simple,
one or two in number

c. Thecate; posterior end of cup _Metacinetidae_
drawn out into stalk; walls
perforated for exit of tentacles

d. Stalked or unstalked; globular; _Podophryidae_
tentacles of different kinds, some (2 genera *_Ephelota_,
knobbed, others pointed *_Podophrya_)

e. Naked or thecate; stalked or not; _Acinetidae_
tentacles numerous, usually
knobbed and all alike

f. Naked; athecate; tentacles _Dendrosomidae_
numerous, all alike, knobbed and
grouped in tufts. They may be
simple or branched.

g. Sessile forms resting on basal _Dendrocometidae_
surface or on a portion raised
like a stalk; tentacles many;
short and knobbed; distributed
on apical surface or localized
on branched arms

h. Stalked or sessile; tentacles _Ophryodendridae_
long, rarely knobbed, supported
on proboscis-like processes

* Presence at Woods Hole indicated by asterisk.

Genus PODOPHRYA Ehr. '33.

(Buetschli '88; Stein '59; Perty '52; Cienkowsky '55; Quenn. '69;
Hertwig '77; Maupas '81.)

The body is globular, with tentacles radiating in all directions. The
tentacles may be very short or very long. The stalk also is either
short or long, and some species form stalks but rarely (_P. libera_).
The macronucleus is centrally placed and globular to ovoid in form.
The contractile vacuole is usually single. Reproduction takes
place by division; the distal half developin