There are three families of shells which are much sought after by conchologists, these are the top shells (Trochidæ), the turban shells (Turbinidæ) and the pheasant shells (Phasionellidæ). Altogether they embrace nearly five hundred species which live from the shore between tides to the lowest depths of the ocean. The shells of the top shells vary to a wonderful degree; some are large, others small; some are perfectly plain and smooth while others are ornamented by impressed lines, ribs and granules, some are very thin and delicate while others are large and massive. Many of the species are richly colored with brown, purple, black, green and yellowish, and all are more or less pearly. They are all vegetable eaters. One of the best known is Trochus niloticus, a large, massive shell striped with brown, which is seen on the mantle of many households. One of the prettiest top shells is the ringed top shell (Calliostoma annulatum) found abundantly in some parts of California. The surface is marked by several rows of delicate points and the suture is bordered by a rich line of purple. It lives in the seaweed off shore and may be seen in pleasant weather crawling about among the weeds. During storms or rough weather this frail mollusk sinks to the bottom of the sea. The top shells inhabit many parts of the world, the coasts of Florida and California producing several very handsome and interesting species. The Turban shells include many fine and large shells, a notable species being Turbo marmoratus, the “green turban” of the dealers. This shell is about seven inches in diameter, rich green outside and pearly inside. It is largely used for mother-of-pearl work and for making pearl buttons. It is said that the early Scandinavian monarchs used this shell as a drinking cup. At the present time it is used for ornamental purposes, richly mounted. In Japan the animal is used for making chop suey, being cut in little dice-like pieces. The Pheasant shells are beautifully variegated with red, black, white and brown and are very interesting animals to study alive. When crawling, the left side of the foot moves forward while the right remains stationary, and when the right side moves the left remains stationary. This curious mode of progression has been likened to the canter of a horse. The larger species, with beautifully variegated shells, inhabit Australia, while the smaller species live in the Mediterranean Sea, South Africa, the West Indies and California.