A N I M A 
rotator}' organ may be difcovered : it moves fwiftly in an 
oblique direction. 40. The conJlriEla, is of two kinds ; 
viz. of a pale yellow, and of a white colour : they move 
by fixing their tail to the place where they are, and then 
extending their body as much as poflible : fometimes they 
turn round upon one of the points of their tail; at other 
times they fpring forward with a jerk : when at reft they 
open their mouths very wide. 41. The togata, has a con¬ 
vex body, filled with molecules, and of a dark colour ; the 
hinder part fomewhat longer than the fore part; the lat¬ 
ter ciliated. 42. The rotatoria, or wheel animal, is fome¬ 
times of a globular, and fometimes of a conic, lhape : it 
puts out its wheels, lwimming vigoroully through the w'a- 
ter in fearch of food; or elfe, fixing itfelf by the tail, 
works the wheels in fuch a manner as to bring its food to 
it. It is found in rain-water that has flood for fome time. 
The molt remarkable part of this animalcule is its wheel- 
work : this conlifts of a couple of femicircular inftriuncnts, 
round the edges of which many little fibrillae move tliem- 
felves very brilkly, fometimes with a kind of rotation, and 
fometimes in a trembling or vibrating manner. When in 
this date, it fwims along with a great deal of fwiftnefs, 
feemingly in purfuit of its prey. Sometimes the wheels 
feem to be entire circles, armed with fmall teeth, like 
thofe of the balance-wheel of a watch, appearing project¬ 
ed forwards beyond the head, and extending fiaeways 
fomewhat wider than its diameter. The teeth or cogs of 
thefe wheels feem to (land very regularly at equal diflan- 
ces; but the figure of them varies according to their pofi- 
tion, the degree of their protrufion, and perhaps the will 
of the animal itfelf. The different appearances of its 
wheels are reprefented in the plate, at fig. 10, 11, 12, and 
13 ; and fig. 14 and 15 fliew this animalcule in its globu¬ 
lar ftate. 43. The furcata, is commonly found in water, 
and has a cylindric body with a rotatory organ, confiding 
of a row of hairs at the apex : the tail is divided into two 
parts, turning a little inwards. 44. The catulns, is com¬ 
monly found in marfhy waters : the anterior part is con¬ 
nected to the body by a little neck ; and it occafionally 
fliews a fmall rotatory organ : its motion is rotatory, but 
in various directions. 45. The canicula, is cylindrical, the 
aperture plain, with a fhort articulated tail divided into 
two parts. 46. The fielis, has a large body, the apex of 
an equal thicknefs, obtufe, with rotatory filaments. 47. 
'Ihefientorea. See the article Polypus. 48. The facialis, 
when confiderably magnified, appears like a circle fur- 
rounded with crowns or ciliated heads, tied by fmall thin 
tails to a common centre, from whence they advance to¬ 
wards the circumference, where they turn very brifkly, 
occafioning a kind of whirlpool, w'hich brings its food. 
When one of them has been in motion fora time, it flops 
and another begins; fometimes two or three may be per¬ 
ceived in motion at once: they are frequently to be met 
with feparate, with the tail flicking in the mud. 49. The 
fiofculofia , appears to the naked eye like a yellow globule 
adhering to the ceratophyllon like a little flower or a heap 
of yellow eggs. When magnified, they are feen to confifl 
of a congeries of animalcula conftituting a fphere from a 
mouldy centre. They contraCl and extend their bodies 
either alone or in fociety, and excite a vortex in the water 
by means of a difk. When they quit the fociety and aCt 
lingly, they may be obferved to confifl of a head, abdo¬ 
men, and tail. 50. The citrina, is found in ftagnant water; 
the head full of molecules, round, every w'here of an equal 
fize, and very tranfparent: both fides of the orifice are 
ciliated, and each has a rotatory motion. 51. The piri¬ 
formis, is fomew hat oval, with a very finall retradlile foot, 
which it can draw within itfelf. 52. The tuberofia , lias a 
broad upper part, with two projeflionsat the anterior end, 
furnifhed with a number of fibrillas, which produce a cur¬ 
rent of water by their vibration, and thus collect food for 
the animal. 53. The ringens, is pear-fliaped, pellucid, 
the middle of the aperture convex, both fides ciliated, the 
pedicle four times fliorter than the body. 54. The incli- 
nans, has a pendulous head; the anterior part truncated, 
Vol. I. No. 46. 
L C U L E. 7 z S 
and occafionally contrafling itfelf twice as fhort as the pe¬ 
dicle. It is fiiaped like a tobacco-pipe, and is reprefented 
in fig. 16 of the plate. 55. The vaginata, is erect, of the 
lhape of a truncated egg; the pedicle is contained in a 
fheath. 56. The globularia, is frequent among the cyclo- 
pa quadricorni. It has a finall fpherical head, with the 
aperture of the mouth ciliated. 57. The lunar is,, has "a 
fmall goblet-fhaped head, the margin of the orifice protu¬ 
berant, ciliated on both fides, with undulating hairs, and 
the pedicle eight or ten times the length of the body. 58. 
The convalaria , or bell-animal, dwell in colonies together 
in a flinty kind of mucilaginous care; w hich, out of the 
W'ater, has no determinate form, but, when expanded there¬ 
in, has fome refemblance to the figure of a bell with its 
mouth upwards. Thefe bells, or colonies, are to be found 
adhering to the large leaves of dunk-w eed, and other aqua¬ 
tic plants. The whole colony together has a povver of al¬ 
tering the pofition of the bell, or even of removing it 
from one place to another; and hence this bell is feme- 
times found Handing perfectly upright, as reprefented at 
fig. 17 in the plate, with the little animals attached to it. 
Though no eyes can be difcovered, yet thefe animalcules 
have a perception of the light: for, when kept in the dark, 
they always remain contracted ; but on being expofed to 
the light of the fun, or of a candle, they conltantly extend 
their arms, and fliew evident figns of being pleafed. 39. 
Th e nutans, has a fimple pedicle; twifts itfelf ipirally ; is 
extremely flender, with a kind of cap on its head. 60. 
The nebulifera is narrow at the bafe ; open and truncated 
at top; the margin feemingly furrounded with a ring: 
but, when the aperture is ftuit, the animalcule is of the 
fhape of an egg. 61. The annularis, is vifible to the na¬ 
ked eye; the head an inverted cone, convex when the 
mouth is illut, but truncated when it is open; with a pro¬ 
tuberant edge. 62. The acinofia inhabits that whitifh fub- 
ftance which often entirely covers plants, wood, (hells, &c. 
When this fubftance is examined by the microlcope, it 
appears to be wholly compofed of living animals of the 
polype kind. 63. The faficiculata, has a rotatory organ, 
which may fometimes be feen projecting beyond the aper¬ 
ture. A congealed green mals which is often found fwim- 
ming about in ditches is compofed of myriads of thefe ani¬ 
mals, which are not vifible to the naked eye, and when 
magnified appear like a bundle of green flowers. 64. The 
hians, refembles a citron; the apex is truncated, the bafe 
narrow, and a gaping cleft is obfervable, defeending from 
the apex to one third of the body. 65. The bellis, is of a 
yellow colour, and much refembles the flower of a daify ; 
is ciliated round the margin of the head, and moves in a 
rotatory manner. 66. The gamclla, has a long pedicle, 
conftantly furnifhed with two fmall heads. 67. Theawa- 
Jlatia. Seethe article Polypus. 68. Th epolipina, when 
viewed through a fmall magnifier, appear like fo many 
little trees: the upper part, or heads, are egg-fliaped, the 
top truncated, the lower part filled with inteflines ; the 
branches thick let with little knobs. 69. The racemofia, is 
only diflinguifhed from the vorticella focialis by always 
adhering to the fides of the veflel in w hich it is placed. 
By the microfcope, we difeover a long pedicle flicking to 
the tides of the vefiels, from which proceed an innumera¬ 
ble quantity of cryflalline pellucid pearls; which, toge¬ 
ther with the llalk, are varioufly agitated in the wa¬ 
ter. Sometimes they move feparateiy ; fometimes they 
are drawn down to the root, and in a moment expanded 
again. 
XVII. Brachionus: a contraClile worm, covered 
with a (hell, and furnifhed with rotatory cilia. 1. The 
Jhiatus, has an oblong pellucid fhell, capable of altering 
its figure. The apex is truncated, with fix fmall teeth on 
the edge of it, twelve longitudinal ftreaks down the back, 
the bafe obtufe and fmooth. The animal itfelf is of a yel¬ 
low colour, cryflalline, and mufcular ; now and then put¬ 
ting out from the apex tw'o or three little bundles of playing 
hairs, the two lateral ones fliorter than that in the middle : 
it is found in fea-water. 2. Th e fyuamula, lias an univalve 
2 Y orbicular 
