356 HELMINTHOLOGY. 
fnail, (helix vivipara,) as given by Muller, in the aft of 
parturition. The head of the parent fnail is feen 
emerged from the fhell, juft far enough for the orifice 
in the fide of its'neck, (called; in all thefe -vermicular 
tribes, the lateral fore,) to protrude'the fexual organ 
charged with its young, one ofjwhich is (hown advanc¬ 
ing into life, completely formed; and, fo foon as its 
young are delivered, the membrane or womb is redrawn 
within the pore. The fhell is very white, with three 
brown bands (haded with yellow ; the fnail is red. In 
feme varieties (particularly in that defCribed by Lin¬ 
naeus; | 3 ) the fhell is riiore fhining and glofly, and the 
included animal of a blackifh colour. 
Fig. i r, is a correct delineation of the buccinum unda¬ 
tum, in its natural creeping pofture, with the body 
wholly protruded, and the limax carrying its fhell 
upon its back. The operculum is a ftriate horny fliield 
affixed to its tail; and when the animal retires to a qui- 
efeent ftate, the extremity of the tail laps over the head, 
and then the fliield or operculum exa'ftly clofes the aper¬ 
ture of the fhell. At a, juft above the canal or fiphon, 
are fhown three of its ovula or eggs. This is an inhabi¬ 
tant of the European feas, and is regarded as a fine fpe- 
cimen. 
Fig. 12, exhibits that curious univalve fhell, called 
Jlrombus pes pelicani , the pelican’s or corvorant’s foot, 
witli the Umax advancing from it, having its head and 
tail already put forth, and its horny operculum adher¬ 
ing to the pofterior extremity, as in the preceding ge¬ 
nus, It is an inhabitant of the European and American 
feas,; and the fhell is valuable. 
Fig. 13, reprefents that curious fpecies called bulla 
akera, of its natural fize. It is fhown, firft (landing on its 
bafe, with the back of.the fhell in front; and fecondly, 
lying proftrate, with,.the little animal in its quiefeent 
pofture. In form, it has the exaft refemblance of a hy¬ 
datid, its body a gelatinous or membranaceous veficle, 
appended to a fmall neck and head, with tranfparent 
globules, filling the abdomen like young tania hydatigena. 
This is evidently the ovarium, filled with ovula in an 
advanced ftate. The animal is a limax, generally found 
attached to fea-weed. It is of an afh-brown colour; 
its body is marked with brown channels, and truncated 
on the fore-part; it protrudes from a large gelatinous 
mafs, as if coming out of a (heath! The eyes are like 
two black points at a diftance from each other in the 
fore-part of the body ; and there is not the lead indica¬ 
tion of feelers. The margin of the body is lometimes 
fo bent as to have fome refemblance to an ear. The ge¬ 
latinous mafs, with which the hind-part of the fnail' is 
furrounded, is numeroufly Tpotted with brown. A 
fmall pellucid and thin membrane feems to cover the 
outfide of the fhell, and another membrane to clothe the 
infide ; this gives the fhell, when the animal is in it, are-' 
ticulated appearance on the outfide, of a brown colour 
with pate fpecks. The animal, when put in a dry-place, 
does'not, like moll teftaceous'fifh, retire into its fhell, 
\bu ; t,,with the gelatinous mafs above-mentioned, remains 
out of the fhell, which is fcarcely capacious enough to 
contain the-whole. Muller obferved it among the fuci, 
or l'ea-weed, of the Kragoer rocks, on the coaft of Nor¬ 
way. 
Fig. 14,'the treehus cincrarius, turned on its back, with 
its head and horns protruding, and its body drawn with¬ 
in the fhell, while its feet, and the horny margin of its 
belly, form an orbicular fhield or operculum over the 
aperture. Fig. 15, (hows the fame animal wholly ex¬ 
tended from its (hell, with the tentacula exferted. This 
fpecies is ranged in the firft divifion of the trochi, isfel- 
dom larger than a pea, .and is found on all our fhores. 
Ibis a.limax. 
Fig. 16, a minute variety of the turbo, or wreath, with 
the,anknal anvancinginits natural creeping pofture,bear-- 
i:rg the (hell tied by a membrane to its back, as .is‘the 
cafe with nearly all the univalve tribe, juft.as we lee 
exemplified in our common garden-fnail. 
Fig. 17, the patella anomala , or anomalous limpet. It 
is a very fingular fpecies. The animal poffeffing the 
limpet fhell, is faid to be a limax ; but this individual 
differs from all others, either of its own or of other ge¬ 
nera. This animal is formed of two tough fpirally- 
twifted reddifh lobes, fringed round the whole length, 
the fringes confiding of bluiffi rigid crifp hairs or fila¬ 
ments, united to the lobes by a blue tendon : the ova¬ 
ries confifl of two vafcular bodies, foliaceous or branch¬ 
ed, and of an orange colour; the ovula are globular, 
and of a vvhitifli grey while in the ovarium; purple 
when firft excluded, and orange when the young are fit 
for burfling into life. The foliated ovaries, with three 
of the eggs, are correftly exhibited at b. In its natural 
ftate it is about the fize of a filver penny; but is here 
' confiderably magnified in order to difiinguifh its fingular 
conitruftion. 
Fig. 18, the Jerpula fpirorbis, very much magnified, to 
fliow its beautiful ftrufture. The fhell is delicately 
white, and fpirally contorted, growing lefs towards the 
centre. The animal is a terebella, furnifhed with an 
elongated probofeis or fucker, enlarged at the extre¬ 
mity into a cup-fhaped mouth, white externally, and 
deep red internally, which it can advance and withdraw 
at pleafure. ‘The head is likewife furnifhed with.fix 
pinnated or branched tentacula, which it throws out to 
fecure its food, and draws wholly within the (lie IF when 
at reft, the aperture of which is clofed by the cup-fhaped 
extremity of the probofeis, which then ferves as an or¬ 
bicular fhield or operculum. Fig. 19, exhibits a group 
of thefe minute ahimals in their natural ftate and fize,- 
as found attached to the fronds of different fpecies of 
fuci, which have then the appearance of being orna¬ 
mented with filver fpangles. 
Fig. 20,the fabella alveolata, found in confiderable maffes 
of a tubular conflriiftion, and of the appearance of ho¬ 
neycomb, adhering to the bottoms of rocks, on the Bri- 
tifli coafls, and on all the European fhores. Every tube 
is furnifhed with an inhabitant; and as they increafe in 
fize, they enlarge the capacity of their tubes, and confe- 
quently of the mafs of materials which contains them. 
They grow from two to three inches in length, and are 
oviparous. The animal is a;nereis, furnifhed ori the 
head with a double row of tentacula, down the centre 
of which is its longitudinal mouth ; the whole bordered 
.■with a larger feries, and of a pearl-like polifli. Thefe 
are all moveable at the will of the animal, in different 
directions, and for the purpofes of its fuftentation. It 
has fix cirrhated fins or feet, three on each fide, whereby 
it moves itfelf forward in its tube ; and as it advances, 
it forms to itfelf a new cruft or fhell. About the cen¬ 
tre.of the abdomen is placed a circular body, which-is 
the matrix 6r ovarum, whence the eggs are excluded, 
adhering to the parent animal till they emerge into life, 
when they .are excluded at the month of the tube to 
form new habitations or combs for themfelves.—See all 
thefe gene/a more particularly deferibed, and their na¬ 
tural hiftory elucidated, under their refpeftive titles in 
this work. 
ZOOPHYTES, or PLANT-LIKE WORMS. 
This order feems deftined by nature to conneCt the 
animal with the vegetable life; and hence the indivi¬ 
duals clafled under this^arrangement, have been pcca- 
fionally denominated the lajl of animals, and the Jirft of 
plants. Mod of them take root, as it were, and grow 
up into (terns; multiplying life in their branches and 
deciduous buds, and in the transformation of their ani¬ 
mated bloffoms or polypes, which are endued with fpon- 
taneous motion. Plants therefore refemble zoophytes, 
but are deftitute of animation, and the power of loco¬ 
motion ; and zoophytes are as it were plants, but fur¬ 
nifhed with fenfation, and the organs of fpontaneous 
motion. Of thefe, fome are foft and naked, properly 
called zoophytes-, others are covered with a hard ihell, 
thence denominated lithophytes. Of this laft divifion the 
