MARINE PROTOZOA FROM WOODS HOLE. 
443 
covered with fine cilia, and the periphery is uniformly studded with large trichocysts, except along 
the furrow. Food consists of dinoflagellates and other small forms. Color dark brown to black. 
Length 330// ; width 200/c 
This form differs considerably from the fresh -water Frontonia leucas as described by Schewiakoff ’89, 
especially in the extreme length of the peristomial furrow, in the position of the nucleus and contractile 
vacuole, and in the nature of the water canals. These in the Woods Hole form are very irregular in 
size and very much branched, not uniform as in Lieberktihn’s (see Biitschli) figure of Frontonia leucas , 
nor radiating as in Schewiakoff’ s description. This may be the same species as Frontonia marina , of 
Fabre-Domergue ’91, whose description and figure I have not seen. 
Genus COLPIDIUM Stein ’60. 
(Biitschli ’88; Maupas’83.) 
The general form is oval, slightly compressed laterally with the dorsal side strongly arched. The 
ventral side is slightly incurved. The anterior end is somewhat smaller than the posterior end, 
which is broadly rounded. The mouth is placed some distance from the anterior end in an oral 
depression and opens into a tubular oesophagus. There are usually two undulating membranes 
which do not extend beyond the mouth borders. The right undulating membrane extends down 
into the oesophagus and appears to be attached to the walls of the latter. The body stripes in front 
of the mouth are twisted to the left. The anus is terminal and the contractile vacuole may be termi- 
nal or situated forwards in the dorsal region. The macronucleus is spherical and has one micronucleus 
attached. Food consists mainly of bacteria. Movement rapid, but interrupted. 
Fresh and salt water, common in infusions. 
Colpidium colpoda Ehr., sp. Fig. 38. 
Synonyms: Colpidium cucuUus Kent ’81; C'. striatus Stokes ’85; Kolpoda cucullus Duj. ’41; Paramoecium colpoda Ehr. ’38, 
Quennerstedt ’67; Plagiopyla nasuta Kent ’81, G. & R. ’86; Glaucoma pyriformis G. & E. ’86; Tillina campyla Stokes ’85, ’88. 
The body is oval, somewhat larger posteriorly, and a little compressed dorso-ventrally. The 
anterior end is twisted a little from the right to the left (more evident in fresh-water forms), and leans 
somewhat toward the ventral side. Under this portion, on the ventral side, lies the mouth in a large 
depression just above the middle of the body. The entire body is covered with uniform and delicate 
cilia, which are placed in longitudinal rows. These rows are almost straight on the dorsal side, but 
bend on the ventral surface, following the contour of the twisted anterior portion. The endoplasm is 
finely granular; the oesophagus leading into it is very distinct. Schewiakoff (’89) describes two 
membranes, an inner and an outer; Maupas (’83) describes them as right and left. In the present 
species I was able to make out only one. The macronucleus is central, spherical in form, and bears a 
single minute micronucleus. The contractile vacuole is posterior and dorsal to the long axis of the body. 
The anus is ventral to this axis and also posterior. Length 45/<; width 20/4. Common. 
This marine variety is much smaller than the fresh-water form and the form differs in a number 
of respects, viz, in the anterior torsion and in the structure of the mouth. These may be, however, 
only individual variations of a widely spread species, and I believe it is perfectly safe to describe this 
as Colpidium colpoda. 
Genus URONEMA Duj. ’41. 
(Quennerstedt ’69; Cohn ’66; Kent '81; Biitschli ’81; Schewiakoff ’89; Shevyakov ’96.) 
Minute forms; colorless and constant in body form. The form is oval, slightly compressed on the 
ventral side, while the dorsal side is distinctly arched. The membrane is distinctly marked by rather 
widely separated strise. These occasionally have a spiral course about the body; in all cases they 
can be easily counted. The mouth is large and placed near the center of the ventral surface. It is 
sometimes approached by a very shallow depression or peristome from the anterior end, and marked 
by two rows of cilia. An undulating membrane extends down the mouth. (Esophagus absent. A 
long, stiff bristle extends outwards from the posterior end. The contractile vacuole is terminal or 
subterminal and near the anal opening. The macronucleus is spherical, centrally placed, and with 
one micronucleus closely applied. Movement is rapid and usual forwards in a straight line, often 
found resting, however, with outstretched cilia in contact with some foreign body. Food mainly 
bacteria. Fresh and salt water, usually in decomposing vegetable substances. 
