The Marble Turban-Shell, ([Turbo marmoratus].)
There are as many as thirty or forty species of the Turban-shell. The Marble Turban, Turbo marmoratus, is the largest, being as much as four inches across; it is found in the Indian Ocean. The colour of this shell is of a brownish green, of greater or less intensity. It is ornamented by eight or ten narrow transverse belts, consisting of a series of white or brownish spots. This is one of those shells whose substance, after the outer coat is removed, is of the nature of mother-of-pearl.
The Turbo littoreus (the Shore Turban), is the well-known periwinkle, with which our rocky coasts abound.
The Imperial Top-Shell, ([Trochus imperialis].)
These shells have received their name from their resemblance in form to a boy’s top. They are all marine shells, and the apex of their spire is always very sharp-pointed. In some places they are called flat-mouthed snails. The greater number of these shells, (and the species are very numerous,) are of a beautiful pearly substance, and many of them are also elegantly marked with longitudinal ribs; there are as many as seventy species,—the larger and more elegant are only found in the seas of hot climates.
Haliotis iris.Scalaria pretiosa. Neritina pulligera.
The Precious Scalaria, ([Scalaria pretiosa].)
This shell is noted for its rarity, and for the singular arrangement of its whorls, which do not touch each other, and appear as if they were only connected by the ribs with which the shell is adorned. Like the turbans, the inhabitants of the Scalariæ are found on the sea-coast, on rocks and large stones, between high and low water mark. The native place of the Scalaria pretiosa seems to be uncertain; Lamarck, and several others, believe it comes from the East Indies, while others consider it an inhabitant of the Mediterranean. So great was the rage some years back, to possess a perfect specimen of this shell, that as much as twenty or thirty pounds, and even more, has been given for a well-preserved specimen. Travellers relate that the Scalariæ are much sought after and highly prized by the women on the coast of Amboyna, and at Batavia, where they are used as earrings, and in forming necklaces. They are, although rarely, as much as four inches in length. It is said, that there was a specimen in the cabinet of the empress Catherine of Russia, still larger; but the most usual size is from one to two inches in length. A fine specimen of this shell ought to be semi-transparent like porcelain, of a light brown, tinged with rose-colour, and the ribs of a beautiful opaque white.