394 
Animals binated. Fam. 7. Cymbium. Fam. 8. Auris cochlea. 9. 
which inha- Cyi; n d r i, Fam. 10. Voluta. Fam. 1 1. Globofa. Fam. 1 2 . 
. * ^ e a ', Caflides. Fam. 13. Trochi. Fam. 14. Cochleae. Fam. 
15. Buccina. Fam. 16. Murex. 
II. Bivalves compofed of 3 orders. 
Order I. With unequal valves, and fliut clofe. 
Fam. 1. Peflen. Fam. 2. Spondylus. Fam. 3. Odre- 
uhl Fam. 4. Anemia. Ord. II. With equal valves, 
Chap. II. 
andftiutclofe, is divided into three fe£Hons. Seel. I. Mult- Animals 
articulate. Fam. 5. Peftinoides. Fam. 6. Peflunculi. w ^ ,c h mha- 
Fam. 7. Area. Se£t. 2. Articulate. Fam. 8. Pe&un- , blt Sll<r “ s ‘. 
cuius. Fam. 9. Tellina. Fam. 10. Placenta. Seft. 3. 
Inarticulate. Fam. 1 1. Margaritifera. Fam. 12. Muf- 
culus. Ord. III. With valves that never Ihut clofe, 
Fam. 13. Chama, Gapers. 
III. Multivalves contain one order. Fam. 14, 
Pholas. Fam. 15. Anatiferae. Fam. 16. Balani. 
CONCHOLOGY. 
CHAP II. OF THE ANIMALS WHICH INHABIT SHELLS. 
1.5 
Generic BEFORE We proceed to the clafiincation of lhells, 
oDetUce* we here give a Ihort defeription of the animals 
ous animals, which inhabit them. Of thefe, however, a minute and 
accurate anatomical defeription is not to be expected 3 
for little more is known of the drudlure of thefe ani- 
mals than what has been given by naturalids concern- 
ing their external charadlers. 
Some of the animals, which inhabit (hells, are alfo 
found in the mollufca date 3 that is without any tefta- 
ceous covering. Such, for inflance, is the Umax, or 
fnail. 
The animals which have been found inhabiting 
(hells are th© following •, viz. Doris, Triton, Afcidia, 
Tethys, Limax, Spio, Amphitrite, Terebella, Ne- 
reis. 
Doris . — The body is creeping, oblong, and flat be- 
neath 3 the mouth is placed below on the forepart 5 
vent behind on the back, and furrounded by a fringe. 
Feelers two or four, fituated on the upper part of the 
body in front, and retraftile within the proper re- 
ceptacles. 
The animal which inhabits the chiton belongs to 
this genus. 
Triton . — The body is oblong, and the mouth is fur- 
nilhed with an involute fpiral probofeis : tentacula or 
arms 1 2, fix on each fide, divided nearly to the bafe. 
The hind ones cheliforous. 
The triton inhabits different fpecies of lepas. 
Afcidia . — The body is fixed, roundifli, and apparent- 
ly iffuing from a (heath 3 apertures two, generally 
placed near the upper end, one beneath the other. The 
animals are found in the fea, and adhere by their bafe 
to rocks, (hells, and other fubmarine fubflances : they 
are more or lefs gelatinous. The only powers of 
motion which they poffcfs feem to be that of con tract - 
ing and dilating themfelves alternately; by. which 
means they are enabled to throw out the water which 
they take in with confiderable force. 
This animal inhabits the pholas, folen, fome fpecies 
of the mya, maftra, and other bivalves. 
Tethys . — The body is detached, rather oblong, 
fiefhy, without peduncles : the mouth is furniihed 
with a terminal cylindrical probofeis, under an ex- 
panded membrane or lip : apertures two, on the left 
fide of the neck. 
l ire tethys inhabits 2 great proportion of bivalve 
(hells, as many fpecies of tellina, cardium, ma£lra, ve- 
nus, oftrea, and others. 
Limax . — The body is oblong, creeping, with a fleff.y 
kind of (liield above, and a longitudinal flat dife be- 
neath : aperture placed on the right fide within the 
(hield : feelers 4, fituated above tire mouth, with an 
eye at the tip of each of the larger ones. 
The animals belonging to this genus inhabit the 
turbinated univalve (hells ; but it appears that all the 
animals which inhabit thefe (hells do not exactly cor- 
refpond with the. above generic chara&ers. 
Spio . — The body projecting from a tube, jointed 
and furniihed with dorfal fibres ; peduncles or feet rough 
with bridles, and placed towards the back ; feelers 2 3 
long, fimple ; eyes 2 ; long. 
This animal inhabits fome fpecies of fabella. 
Amphitrite . — Body projecting from a tube, and an- 
nulate ; peduncles or feet fmall, numerous, with lateral 
fafciculi, and branchiae ; feelers 2 , approximate, fea- 
thered ; no eyes. 
The amphitrite inhabits fome fpecies of fabella and 
ferpula. 
Terebella . — Body oblong, creeping, naked, furniih- 
ed with lateral fafciculi, or tufts, and branchiae 3 
mouth placed before, furni(hed with lips, without teeth, 
and protruding a clavated probofeis; feelers numerous, 
ciliated, capillary, and placed round the mouth. 
This animal is an inhabitant of many fpecies of den- 
talium, ferpula and fabella. 
Nereis . — Body long, creeping, with numerous late- 
ral peduncles or feet on each fide ; feelers fimple, rare- 
ly none; eyes 2 or 4, rarely none. According to 
fome naturalids, the nereis inhabits fome fpecies of 
fabella. 
Sepia . — Body flelhy, receiving the bread in a flreath, 
with a tubular aperture at its bafe ; arms 8, befet 
with numerous warts or fuckers, and in mod fpecies 2 
pedunculated tentacula ; head Orort 3 eyes large 3 mouth 
refembling a parrot’s beak. 
The animal which inhabits the argonauta is confi- 
dered by naturalids as belonging to this genus. 
Clio . — Body oblong, natant, generally fheathed and 
furniihed with two dilated membranaceous arms or 
wing-like proceffes 3 tentacula 3, befides 2 in the mouth. 
According to fome naturalids, it is an animal be- 
longing to this genu?, which inhabits the argonauta. 
CHAP, 
