'It is a fmall animaiculum, gelatinous, white, -opake, -without
- any vifible inteftines, the.upper part convex o r gibbous ; -many
of them were found in an infufion of hay, alfo in other infufions.
126. Gercaria Inquiéta. Fig. 31 and 32, Plate XXV.
Cercaria mutabilis convexa, cauda lævi. Changeable -convex
-cercaria, with a fmooth tail.
This animaiculum fo often changes the form o f it’s body, that
it is not eafy to defcribe it ; it is fometimes fpherical, fometimes
like a long cylinder, at others of an oval figure, white, gelatinous,
the tail is filiform and flexible, the upper part vibrating
vehemently, no vifible vifcera, a pellucid globule may be obferved
at the bafe, and two very fmall black points placed near the top
a t d, Fig. 32 ; whether they are eyes to the animaiculum is not
inown. Was found in fait water, a, Fig. 31, the body, b the
tail.
127. Cercaria Lemna, Fig. 33, 34, and 35.
■ Cercaria mutabilis, fubdepreffa, cauda armulata. Mutable
cercaria, fomewhat flattened, with an annulated tail.
This animaiculum puts on fuch various forms, that at firft fight
it appears like the proteus. o f Baker, though it is altogether
■ different.
The body is capable of being contracted or extended, o f the
ïhape o f an oblong pear, or triangular, kidney-fhaped. The tail
fhort,
M i c r o s c o p i c a l E s s a y s . 5r r5i1
ffiort, thick, and annulated, fometimes long, bending, cylindric
and without rings. It vibrates, when it is llretched out, with fo
much velocity, that it appears as it weye double! The inteftines
not very, diftinft, near the apex a fmall pellucid globule is perceivable,
that Muller takes to be it’s mouth; two black points
which are near it,, but with difficulty difcovered, he fuppofes to
he the eyes. It draws the tail fometimes into the body. Fig. 33
a, the body rather fpherical, b the ta il; Fig. 34, c, the triangular
body; Fig, 35, the body extended,- e e the eyes, f f the how-
els, g aJarge veficle,. h.a fmaller one.
It walks flowly after taking three or fourfteps ; it extends the
tail, erefiing it perpendicularly, ffiaking and bending it; in this-
flats it rdembles much the leaf o f the lemna.
128. Cercaria, Turbo. Fig. 30, Plate XXV.
Gercaria globulbfa, medio coarftata, cauda unifeta. Globular,
cercaria, the middle contracted, with a tail,like a hriftle.
Partly of an oval,, and partly o f a fpherical ffiape, pellucid,!
and of a talcy appearance. It feems to be compofed o f two glo-.
Bular bodies, the lower one being the fmalleft ; this figure is oc-
cafioned by the contraction at the middle. There are two black
points, like eyes, at the upper part of the animaiculum, even with
a tranfverfe line which crofles the top o f this little creature; feve-
ra^.large globules may be difcerned, the tail is fometimes quite ■
ftrait, fometimes turned.back on the body. It is to be met with
among the duck-weed..