Among marine mollusks none stand so favorably in the eyes of collectors
or are so beautiful as the Cypraeas, or Cowry shells. With their glossy
coats and varied colors they are indeed gems of the ocean, and it is
little wonder that the conchologist has placed them first among the many
families of marine shells.
The name Cypraea comes from Cypris, one of the names of the goddess
Venus. About two hundred recent species have been described and they are
found in nearly all parts of the world, though more numerous in the
tropics and sub-tropics, where they live on coral reefs and under rocks.
As in many other genera of shells the Cowries living in the tropics are
more brilliantly colored than those from more temperate climes, a
condition due to the large amount of sunshine and high temperature, both
of these factors being essential to the secretion of color in the
pigment cells of the animal.
The animal which inhabits a Cowry shell is a curiosity. The foot is
large and spreads out in a wide mass, enabling the animal to glide along
quite rapidly. The mantle lobes are folded over the back of the shell
and are beset with many little tuft-like organs which stick out like
young shoots on a plant. The mouth is placed at the end of a rather long
snout or rostrum and the eyes are upon the outside of two long, tapering
tentacles, about one-third the distance from the body. When the shell is
young it is covered with a thin epidermis and has a thin, sharp outer
lip, like some snails, but when it is full grown the outer lip rolls
inward, becomes toothed or ridged, as does also the inner lip, and the
aperture becomes a long and narrow slit reaching from the apex to the
base of the shell. The mantle lobes, which are inconspicuous in the
young shell, becomes larger and are reflected over the back, depositing
coat after coat of shelly enamel until the first pattern of the shell,
as well as the epidermis, is covered with a secondary, shining coat. On
most Cypraeas there is a line of paler color, showing where the two
lobes of the mantle meet on the back.
Like many other mollusks the Cypraea is able to dissolve the internal
whorls and thus enlarge the capacity of its shell. This is also true of
Conus, and Murex, and some other marine snails dissolve the spines which
may be in the way when increasing the size of the whorls. The older
naturalists, Lamarck and Bruguiere, believed that the Cypraea was able
to dissolve its outer lip after it had been rolled over and toothed, but
this theory has been proved to be incorrect. They founded their belief
on the fact that some individuals of the same species were larger than
others. This, however, is due simply to individual variation.
The beautiful colors so much admired are deposited by the reflected
mantle and their variety is almost endless. Some are perfectly plain,
white, brownish, yellowish or orange, others are spotted with red,
white, brown, drab or black, and still others are variously banded. The
eyed-cowry (Cypraea argus) has large, dark brown spots on a lighter
background.
In form and sculpture the Cowries present a rather wide range of
variation. The typical form is more or less cylindrical, or pyriform,
while others are flat, oval or egg-shaped. The surface varies from
smooth to spirally lined and pustulose. In size they vary from the
little Trivia exigua, scarcely one-fourth of an inch long, to the huge
Cypraea testudinaria, nearly five inches in length.
Many of the larger species, like the tiger cowry (Cypraea tigris) and
the black cowry (Cypraea mauritiana) have been household ornaments for
centuries and have also served as playthings for young children, who
have held them to their ears to “hear the sound of the roaring sea.”
[Illustration: COWRY SHELLS.
FROM COL. CHI. ACAD. SCIENCES.]
Top row:
Cypraea exanthema (Half grown.)
Cypraea exanthema (Young).
Cypraea exanthema (Florida).
Second row:
Trivia solandri (California).
Cypraea annulus (Indian Ocean).
Third row:
Cypraea erosa (Indian Ocean).
Cypraea lurida (Mediterranean Sea).
Fourth row:
Cypraea spadicea (California).
Cypraea moneta (Philippines).
Fifth row:
Cypraea talpa (Pacific Ocean).
Cypraea mus (Europe).
Cypraea histrio (Indian Ocean).
In habits the Cowries are shy and they are slow in movement, sliding
over the coral reefs and marine vegetation with a sluggish, steady
motion. They present a beautiful sight when viewed through the water,
their brilliant colors vying with those of corals, sea anemones and sea
weeds. They are said to feed principally upon the coral animals.
From very ancient times the smaller Cowries have been used for adornment
or barter. The Cypraea annulus, or ringed cowrie, which was found by Dr.
Layard in the ruins of Nimroud, is said to be the same species which is
now used by the islanders of the Indian and Pacific Oceans to weight
their fish nets and to adorn their persons. In western Africa the money
cowry (Cypraea moneta) has been and is now used as a medium of exchange
in place of gold. Many tons were yearly shipped to England from the
Indian and Pacific Oceans, to be again carried to Africa to barter with
the natives for ivory and other articles.
The number of Cowries which have been given for various articles, with
their value in American currency, is interesting. Thus it is recorded by
the Conchologist Reeve that a gentleman residing at Cuttack in India
paid for the building of his bungalow entirely in Cowries, giving over
sixteen million specimens. The value of these Cowries was four thousand
rupees sicca in Indian money, or about two thousand dollars in American
money. In another place it is recorded that a young wife cost from sixty
thousand to one million Cowries, or from about nineteen dollars to
thirty-seven dollars, while an ordinary wife cost but twenty thousand
shells or about six dollars.
The value of Cowries varies in different countries. In India five or six
thousand may be purchased for one rupee, while in parts of Africa two
hundred Cowries are worth sixteen cents. In Sudan, two thousand Cowries,
which weigh about seven pounds, are worth one dollar. On the west coast
of Africa, where trading in Cowries is largely carried on, the following
gradation of value is recorded by Dr. Stearns:
40 Cowries = 1 string.
2½ strings = 1 pence.
100 Cowries = 1 pence.
50 strings = 1 head of Cowries.
10 heads = 1 bag.
2,000 Cowries = 1 head.
3 heads = 1 dollar.
20,000 Cowries = 1 bag.
In other places the value is about 1s. 3d. for 1,000 shells.
The money cowry is also used as ornaments on the trappings of horses and
elephants, as well as on the persons of men and women. The rich yellow
variety is much sought after by the chiefs of several island tribes, who
permit no one but themselves or their sub-chiefs to wear them.
We may truly say that of all the mollusks, large or small, handsome or
ugly, the modest little money cowry surpasses any in point of economical
importance.
In the Friendly Islands the orange cowry (Cypraea aurantia) is used as a
badge of chieftainship and for a long time specimens were almost
priceless because no one but the chief was allowed to wear this
ornament. Specimens of this species are frequently seen in collections,
with a hole in the back by means of which it was suspended about the
neck of the native chief.
Those who have described the Cowries have given them many fanciful
names, some of which, however, are quite appropriate. Thus we have the
caput serpentis or serpent’s head; the arabica or Arab shell, so named
from the peculiar, hieroglyphic-like characters on its back; the lynx,
pantherina and tigris, each shell resembling the coat of the lynx,
panther and tiger; mus, the rat shell; rhinoceros, the rhinoceros shell;
turdus the thrush, and cervus the deer. Many of the other names are
equally well chosen, as moppa the mop cowry, and pustulata the pustulose
cowry.
It is interesting to note the prices that have been paid for rare
specimens of this family. At an auction held in London many years ago a
specimen of Cypraea guttata brought two hundred dollars, and Cypraea
princeps, another very rare shell, brought the same price. Cypraea
umbilicata once sold for one hundred and fifty dollars, but may now be
had for five dollars. Aurantia, the orange cowry, was once almost
priceless, but is now sold at from twenty to forty dollars. Some of the
lesser rarities are Cypraea scoltii, worth from five to eight dollars,
and Cypraea decipiens, worth from fifteen to twenty dollars. These
extravagant prices need not be paid by any one desiring a collection of
these pretty shells, for the price of a single rarity will suffice to
purchase the majority of the common species. Several private collections
in the United States contain from one hundred fifty to one hundred
seventy species, including a number of the rarities spoken of above.
In connection with the Cypraeas it is interesting to notice other
species of shell money which have been used as money. The North American
Indians used fragments of shells for money, which they called wampum. In
New England wampum was in the form of beads, the manufacture of which
required considerable skill. These beads were cylindrical in form, about
one-fourth of an inch long and half as wide. They were of two colors and
were drilled and strung on long cords.
The quahog (Venus mercenaria) was much used in the manufacture of shell
money because of its two decided colors, pure white and deep purple. The
white beads were called wampum or wompom and the black beads suckauhock,
or black money. In addition to the quahog the whelk Buccinum and the
“periwinkle” or “winkle” were used, the long, white columella being cut
from the shell and made into beads.
We learn from some of the older records that in Massachusetts the wampum
was valued at three beads to a penny or five shillings for a fathom. The
fathom varied in size according to the number of beads allowed by law as
an equivalent to a penny. If this was six, then the fathom contained
three hundred and sixty beads, but if the number was four, then the
fathom was composed of two hundred forty beads. Owing to the
counterfeiting of wampum by the whites, who could make it much quicker
with their tools than could the Indians, the value rapidly fell in later
years and its use was finally discontinued.
On the coast of California the tooth or tusk shells, Dentalium, were
used as money, being strung together as were the beads of the New
England Indians. Those of the better quality were called Phai-Kwa or
hi-qua and represented the highest standard of money. One hi-qua would
purchase one male or two female slaves. The damaged or defective shells
were called kop-kops, forty of which equalled one hi-qua in value. At
one time a single hi-qua was equal in value to about two hundred fifty
dollars. Other shells were also used on the Pacific coast, some of which
were simply strung in the form of beads while others were cut from large
shells. One of the latter was from the large clam, Pachydesma
crassatelloides, and the pieces were called hawock or ha-wok, their
value ranging from four to twenty-five cents. Another clam used was the
Saxidomus aratus.
The little Olivella biplicata was used for beads and was called hol-kol.
They were made by grinding off the apex, which left a hole through the
top of the shell. The Haliotis or abalone was also used and was called
uhl-lo. Pieces of the shell one or two inches in length were cut from
the flat part of the abalone, a hole was drilled in one end and they
were strung like beads. Their value was one dollar each, or ten dollars
for a string of ten pieces. Like the shell money of New England that of
the Pacific coast was counterfeited by the whites and for this reason
the value of the native currency soon declined.
Frank Collins Baker.