Читать книгу The Book of Shells. Containing the Classes Mollusca, Conchifera, Cirrhipeda, Annulata, and Crustacea онлайн

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The Money Cowrie of Guinea is very common on the Indian and African coasts; and is used by many of the inhabitants of Africa as a circulating medium; it is also employed for the same purpose in Hindoostan, particularly at Calcutta, where great quantities are obtained from the inhabitants of the Maldive Islands in exchange for rice.

Cypræa moneta.

Many tons of Cowries are annually shipped from England to Guinea; these having been originally brought from the Maldive Islands to Bengal, and from thence sent into this country. The value of these shells as a circulating medium depends naturally enough on their greater or less abundance.

In Bengal, in general, from 2000 to 2400 are equal in value to a shilling. But in Africa they are much dearer, about 250 being valued at a shilling.

The ssss1 is found of three different forms, according to its age. First, in its extreme youth, when the shell is extremely imperfect, and is like a slender one, without any appearance of the usual characters of the genius. Secondly, when half-grown; it then begins to assume the form of the perfect shell, but is extremely slight, and colourless, and the point of its spire projects. Thirdly, when perfect; it has now received a second deposit of shelly matter, in which its specific colours appear, and its spire is completely hidden. The second deposit with which the shell is covered, is secreted by the two membranous wings of the creature’s mantle, which, in the adult state of the animal, have rapidly increased and become extremely large, so much so, as to be capable of covering the whole of the shell, while the deposition of the new matter is taking place.