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

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The difficulty of procuring and preserving a sufficient number of these shell-fish, must always render the use of this dye very limited; but Dr. Bancroft is of opinion, that it might still be rendered beneficial in staining or printing fine muslins, for which purpose but little colouring-matter is required. No substance, he remarks, will afford a substantive purple of equal beauty and durability, and capable of being applied to linen or cotton with so much simplicity and expedition.

Family ALATA.

This family is distinguished, by having a canal of variable length at the base of its opening, and by the fact of the right margin of the shell changing its form during the growth of the animal.

This curious shell is found in the East Indian seas, and attains a considerable size, as much as six inches. In an early age the projecting claws of this shell are very small, so that its appearance is materially different from that which it assumes at a more advanced period of its growth. It is known as the Spotted Scorpion Shell, and is distinguished from other species of the same genus, by the knotted and granulated appearance of its surface; the opening of the shell is long and narrow, and of a dull violet red, sometimes brownish, on which numerous transverse wrinkles are seen, either of a pure white, or slightly tinged with yellow.