422 CONCH 
canalicit- 6 2. M. (inoothhh, chefnut brctwn,; within party co- 
latus. loured ; focket of the hinge channelled. 
rqftrum. 63. M. oblong, thin, truncated •, beaks (harp and 
carinated ; valves gaping at the end. Amboyna. 
camellu. 64. M. oblong, thin, truncated ; beaks (harp and 
carinated ; valves completely clofed. Japan. 
avonenfis . * 65. M. with a fuboval fhell, of an olivaceous 
brown colour, with concentric wrinkles; fize of the 
M. anatinus , but broader in proportion to its length. 
The pofterior fide generally more obtule and rounded. 
River Avon in Wiltfnire. Montagu , TeJl.Brit . 172. 
Pinna. 3 GEN.-17. PlNNA, Sea-Wing. 
Gen. Char . — The animal a limax ; the fhell bivalve, 
fragile, upright, gaping at one end, and furnished 
with a byffus or beard. Hinge without teeth ; the 
valves united into one. 
Species. 
rudis. 1. P. vaulted with arched fcales, arranged in rows; 
from 12 to 16 inches long, and from 4 to 8 broad ; 
red ; from 6 to 8 grooves. Atlantic, Indian, and Red 
feas. 
pedhnata. 2. P. longitudinally firiated half way ; one fide 
flightly wrinkled tranfverfely ; 3 inches long, 4 broad. 
Indian ocean. 
nobihs. 3. P. firiated, with channelled, tubular, fubimbri- 
cated fcales ; 7-J- inches long, 3-I broad. Mediterra- 
nean, Adriatic, and American feas. 
muricata. * 4. P. firiated with concave, ovate, acute fcales ; from 
3 to 9 inches long, and x to 3 broad. European and 
Indian oceans, Weymouth. 
rotundata . 3. P. with obfolete fcales, margin rounded ; fome- 
times 2 feet long. Mediterranean. 
fquamofa. 6. P. with fine undulated fcales, and flexuous, 
broad wrinkles ; fmaller end pointed and naked; 13 
. inches long, 6 ^ broad. Mediterranean. 
carnea. 7. P. thin, flelh colour, naked, longitudinally 
grooved ; external margin acute and rounded. 
faccata. 8. P. fmooth, fatchel-lhaped ; a little ereCl, and 
(lightly faftigiated ; 3-j inches long, 2^ broad. Medi- 
terranean and Indian feas. 
digit for- 9. P. fmooth, tubular, finger-lhaped, incurved ; ex- 
mis. treme margin membranaceous ; pellucid. 
lobata. 10. P. naked, lobed, ftraw- coloured, with purple 
ftriae. 
vitrea. ix. P. hyaline, with longitudinal, waved ftriae; 
the ftriae with a few fcales, and crofted by other tranf- 
verfe ftriae at the margin. Indian ocean. Very rare. 
incurva. 12. P. narrow, long, naked, carinated, with tranf- 
verfe, undulated wrinkles. Indian ocean. 
bicolor. 13. P. thin, infle&ed at the lateral margin ; yellow- 
ifh, with black brown rays ; thinly ftriated longitudi- 
nally. Red fea. 
xuf.a. 14. P. flattilh, horny, with blackifh rays, fpots, and 
clouds ; and many fmooth ftriae. Southern ocean of 
■India. Red fea. 
vexillum. 15. P. truncated at the outer margin ; dilated, na- 
ked, with a few black clouds ; ftriated longitudinally 
on the fore-part, and tranfverfely wrinkled behind. 
India. Very rare. 
pnpyracea. 16. P. thin, brittle, horny, longitudinally ribbed ; 
extreme margin rotindilh. Indian ocean. 
O L O G 1. Chap. IV. 
17. P. flattilh, flightly incurved, red, with a few fanguinea. 
perpendicular fmooth ftriae ; 3 inches long. 
18. P. very ftraight, thin, and perpendicularly ftri- bullata. 
ated, with tranfverfe, fpinous wrinkles, on the lower 
margin. 
General Obfervations.—ll has been doubted whether 
the animal which inhabits the pinna be a lima?: or flug, 
■according to the opinion of Linnaeus ; and it is even 
■afi'erted, that it has not the fmalleft affinity with this 
animal, but approaches much more nearly to that 
-which belongs to the mytilus. In proof of this, it is 
faid that the pinna poffeffes no locomotive power, but 
remains fixed by its byffus or beard to other bodies ; 
and fo firmly attached, that it can by no means bedif- 
engaged at the will of the animal ; for the fibres are 
ftrongly agglutinated to the fand, gravel, or other ex- 
traneeus bodies within reach. Indeed it feems not 
at all improbable that all teftaceous animals, furnifhed 
with a fimilar beard, are intended by this ftrufiure to 
--remain attached to the fpot where they are originally 
produced. 
This (hell-nfh was celebrated among the ancients on 
account of the cloth which was made of the fine byffus 
or beard by which it is attached. As a rare and coft- 
ly production it brought a high price, and was held in 
great eftimation. At the prefent day even, according 
to the information of modern travellers, the inhabitants 
of Palermo and Naples manufacture gloves and ftock- 
ings from the fame fubftance. 
The pinna has obtained a little reputation for the 
praftice of fome of the moral virtues, in treating a 
finall fpecics of crab with hofpitality and friendlhip, by 
receiving it into the (hell, and defending it agarinlt its 
enemies.' In return for this kindnefs, the crab, like 
the jackall with the lion, aCts the parts of a provider 
and monitor, by warning its hoft of the prefence of its 
prey or of the approach of an enemy. But this friend- 
ly intercourfe accords ill with the nature of the ani- 
mals between whom it is pradtifed. The crab, it is 
far more probable, is a troublefome intruder ; and not- 
withftanding all the fervice he can repay, is confider- 
ed as a very unwelcome gueft, and is indebted for his 
lodging to his own aftivity, and the fluggifti mature of 
his hoft, rather than to his kindnefs and hofpitality. 
III. UNIVALVE SHELLS. 
46 
Gen. 18. Argonauta. Argcnauta, 
Gen. Char. — The animal is a fepia or clio. The (hell 
is univalve, fpiral, involute, membranaceous, one- 
. celled. 
Species. 
1. A. The paper nautilus. Keel or ridge of the (hell argo ». 
(lightly toothed on each fide. The (hell, which is thin 
as paper, brittle, and tranfparent, is white or yellow- 
ifh, with fmooth or knotty ftrias or ribs, which are 
fometimes forked; the keel is generally brownifti. 
This fhell prefents confiderable varieties. Sometimes 
the keel is narrow, and marked with clofe bifurcated 
wrinkles ; fometimes it has a broad keel with tubercu- 
lated ribs ; and fometimes a broad tuberculated keel 
with few and fmooth ribs. 
The Angular ftruCture and wonderful economy of 
this 
3 
