•Pkctenid^. 
Pearl-oyster.- 
-MOLLUSCA.- 
-PECTENID.E. 
375 
Family— SPONDYLIDiE. 
at a supper with Antony, took from her ear one of 
two pearls valued at £80,729 3s. 4d., dissolved it in 
vinegar, and drank it olf. The traveller Tavernier, in 
more modern times, informs us that he saw in Persia a 
pearl, which had been brought from the fishery at 
Catifa in Arabia, and then in the possession of the 
Shah of Persia, which was nearly one and a half inches 
long, ^ths of an inch in diameter, and was valued at 
£110,000. The two great fisheries of pearls are those at 
Bahrein Island, in the Persian Gulf, and in the bay of 
Condatchy in the Gulf of Manaar, off the island of 
Ceylon. The fishery of this latter place varies very 
much in value. In 1798 the revenue derived from it 
to Government reached the large sum of £192,000, but 
in 1828 it only brought £30,612. The Bahrein fishery, 
which includes the whole trade of the Persian Gulf, 
is estimated as worth from £300,000 to £310,000 ! 
The worst and most valueless kinds of pearls taken at 
Ceylon are “ carried to China, to be burned into lime, 
which the rich Chinese use, instead of lime, with the 
betel leaf and areca nut.” — [Bertolucci.) The small 
pearls called seed pearls, from the Persian Gulf fishery, 
find their way in large quantities into various parts 
of India, where they are used in the composition of 
the majoons or electuaries, so much valued by the 
natives for their supposed stimulating and restorative 
qualities. 
THE PEAEI-OYSTER (Margaritiphora fimhriata), 
represented in Plate 11, fig. 21, Margarita margariti- 
fera, when adult, is of a solid thick substance, and of 
a highly polished nature internally. This forms the 
article called in commerce “ mother of pearl,” a sub- 
stance now used in so many ways in ornamental work 
— as inlaying cabinet work, forming knife handles, 
paper cutters, buttons, and constructing toys and 
fancy articles. Immense quantities of these shells are 
annuall}^ imported into Great Britain. “ There are 
three principal kinds, which are worth from £2 to £4 
per cwt. — 1st, The Silver-lipped, from the Society 
Islands, of which about twenty tons are annually im- 
ported to Liverpool; 2nd, The Black-lipped, from 
Manilla, of which thirty tons were imported in 1851 ; 
3rd, A smaller sort from Panama, two hundred tons 
of which are annually imported — in 1851 a single 
vessel brought three hundred and forty tons.” — 
{Woodward.) The animals of these shells are some- 
times used as food. Morier says that those in the 
Persian Gulf are considered excellent, and that there 
is no difference to be perceived in respect of taste 
between them and the common oyster. Most authors, 
however, describe them as unfit for the table. Dam- 
pier, in one of his voyages, found them in abun- 
dance at Gorgonia, coast of Peru. “ The fish," he says, 
“ is not sweet nor very wholesome ; it is as slimy as a 
shell-snail ; they taste very copperish if eaten raw, and 
are best boyl’d. The Indians, who gather them for 
the Spaniards, hang the meat of them on strings like 
Jews-ears, and dry them before they eat them.” In 
another part of the coast of South America, he says 
that they were “ so large, that one stewed is a meal 
for five men.” “ The erew,” he adds, “ate them for 
want of better food.” When stewed with pepper and 
vinegar, they were “very tolerable food.” 
The Thorny oysters have the margins of the mantle 
thickened and furnished with bright eye-spots or ocelli. 
The shell is irregular, attached by the right valve, 
radiately ribbed, spiny or foliaceous. The hinge has 
two large interloeking teeth in each valve. 
Genus Spondylus, or Thorny Oyster. — This 
genus (the only one) has in general a strong thick shell, 
variously ornamented with spines or plates. The 
beaks are apart from each other, and eared. The lower 
valve has a peculiar triangular hinge area, divided by 
a groove and enlarging as it grows older; and the ear- 
tilage is placed in a pit which communicates at its base 
with the external groove. These shells adhere to 
foreign bodies, such as stones, coral, <S:c., by the right 
valve, being cemented to these bodies without the 
medium of any connecting membrane or ligament, and 
becoming modelled to the foreign substance on which it 
lies. In the inner la 3 'er of shell there are left in some 
of the species, as in Spondylus varians — hence called 
the “ Water-clam” — spaces or cavities which are filled 
with water. Similar cavities are found in the Etherice; 
but these are generally like blisters or air bub- 
bles, whilst in Spondylus the quantity of water con- 
tained is often considerable and remains for a length of 
time, perhaps years, after the shell is dry. These 
cavities are produced by the border of the mantle 
depositing shell more rapidly than the umbonal portion. 
There are a good many species, and some of them are 
beautiful shells and adorned with bright and lively 
colours. The genus is represented in Plate 11, fig 22, 
bj' Spondylus regias. 
Family— PECTENID AH {The Scallops). 
The Scallops have a long foot, which secretes a 
byssus. The margins of the mantle are double, the 
inner hanging down somewhat like a curtain and finely 
fringed ; and having at its base a row of conspicuous 
round black spots, like eyes, called ocelli., surrounded 
by tentacular filaments. The shell of the Scallops is 
free, not cemented, and is closed. The beaks are 
placed near each other, and the dorsal edges are pro- 
duced into ears. The ligament is internal, in a central 
pit. The species are numerous ; they generally attach 
themselves by a bj'ssus to rocks and other marine 
bodies, and sometimes cover extensive banks with their 
shells. Their long and angulated foot is not at all 
adapted for crawling, but it is used “ chiefly as an 
exploring organ and to anchor them when required.” 
— {Adams.) The animals are said to possess the power 
of vision ; and the bright spots on the edge of tlie 
mouth are believed by many conchologists to be the 
ej'es. Poli so considers them, and he named the animal, 
“after Juno’s watchman, the Argus, to whose mantle 
you may suppose the hundred eyes of the fabled son of 
Ariston had been transferred.” — {Johnston.) AVhen 
young the Scallops are free and extremely active. 
The fry of the common “ Quin,” as it is called, Pecten 
opercularis, has been particularly noticed by Dr. Lands- 
borough. At the time he observed them they were 
about the size of a fourpenny piece, and were seen in 
