NEW PERITRICHOUS INFUSORIAN. 24.7 
ease to the middle of the body. These appear to be capable of 
motion forwards or backwards, judging from the figures 
given by Claparéde.' In our Infusorian the swift movements 
of the animal rendered these setae quite invisible, and they 
could only be discerned when it was stationary, then as- 
suming the position delineated in fig. 2. 
2. ‘The body (b., fig. 1, 2) is composed of a protoplasm, in 
which are imbedded minute greenish particles, possibly 
derived from the sponge. The outside edge of the proto- 
plasm is free from granules (cf., fig. 6), perfectly transparent, 
and thisis the only apparent differentiation of abody wall, there 
being not the slightest trace of the striz so common in many 
Infusoria. This protoplasm is quite soft. The body slowly 
changes its shape in the most astonishing manner. In fig. 2 
it is represented of the form it usually showed, but in one 
and the same individual it assumed successively the shapes 
drawn in figs. 3, 4, and 5. Whether this continual change 
of shape is or is not natural, if is impossible to say, perhaps 
being due to the effect of confinement. Similar confinement 
seems to affect Trichodina pediculus in much the same way.” 
The body is slightly larger than the disc, and consequently 
in the front view (fig. 1, b.) is seen surrounding the latter as 
a bright granulated border. 
The mouth (m., figs. 2 and 6) is situated in the body at the 
spot where it may be considered as uniting with the disc. 
It is of a moderate size, and leads at once into a ciliated 
pharynx (ph., figs.1, 2), which stretches far into the body 
tending away from the disc. Seen from the front (fig. 1) 
it appears to be ciliated on both sides, but when viewed 
sideways cilia were visible on that side alone which is turned 
towards the disc (cf. figs. 1 and 2, ph.). Hence it may per- 
haps be concluded that this side is flat and ciliated all over, 
the other walls of the pharynx being non-ciliate. 
There was one vacuole (v., figs. 1, 2) constant in its posi- 
tion in all the specimens examined ; filling and bursting 
with the greatest regularity. One or two others occasionally 
appeared (v!., figs. 1, 2). 
With the exception of one specimen there was invariably 
present a greenish body, elliptical in shape and placed in the 
same position, viz. to one side and at a deeper level than 
the pharynx, and small in size. This body I take to be the 
Endoplast (nucleus auctt.), as yet unripe. It was slightly 
granulated, but no other structure was detectible in it (n., 
figs. 1, 2). Acetic acid brought out no further details. 
' Loe. cit., Pl. XIII, figs. 8, 9. 
* James Clark, loc. cit., p. 405. 
