all power of description in the beauty of its colorings. The large Helmet-Shells, of the genus Cassis, are extensively used in the manufacture of cameos.

Genus BUCCINUM: Buccinum, includes several species, of which the CoмMON WHELK, B. undatum, is the type; this is extensively caught in dredges in Europe, as it is eaten, and is also used as fish-bait. It is well known to bore through the shells of other mollusca, and thus to suck out the vital parts. A curious illustration of this habit is furnished by Mr. Stephenson, in describing the erection of the Light-house on the Bell Rock, off the Southwestern coast of England. On the first landing of the workmen there, the limpets, of a very large size, were common, but were soon picked up for bait. As they disappeared, an effort was made to plant a colony of mussels, from beds at the mouth of the river Eden, of a larger size than those which seemed natural to the rock. These larger mussels were deemed likely to prove useful to the workmen, and might have been especially so to the lightkeepers, the future inhabitants of the rock, to whom that mollusk would have afforded a fresh meal as well as a better bait than the limpet; but the mussels were soon observed to open and die in great numbers. The reason of this was not readily discernible, but at length it was ascertained that the whelk had greatly increased, and proved a successful enemy to the mussel. It was repeatedly observed to perforate a small hole in the shell, and then to suck out the finer parts of the body of the mussel; the valves of course opened, and the remainder of the mollusk was washed away by the sea. The perforated hole was generally -such is the instinct of these little creatures-in the thinnest part of the shell; it was perfectly circular, but widened toward the outer side, and so perfectly smooth and regular as to have all the appearance of the most beautiful work of an expert artist. Several subsequent attempts were made to plant mussels in this place, but they were all destroyed by the predaceous whelks.

THE COMMON WHELK.

Another British species of Whelk, the B. lapillus, produces a purple dye, similar to that obtained by the ancients. Mr. W. Cole of Bristol, in 1684, thus described the process adopted in England for obtaining this color: "The shells being harder than most of other kinds, are to he broken with a smart stroke with a hammer, on a plate of iron or firm piece of timber, with

their mouths downward, so as not to crush the body of the fish within; the broken pieces being picked off, there will appear a white vein, lying transversely in a little furrow or cleft next to the head of the fish, which must be digged out with the stiff point of a horse-hair pencil, being made short and tapering. The letters, figures, or what else that shall be made on the linen and perhaps silk too, will presently appear of a pleasant light-green color, and if placed in the sun will change into the following colors, that is, if in winter about noon; if in the summer, an hour or two after sun-rising, and so much before setting; for in the best of the day in summer the colors will come on so fast that the succession of each will scarcely be distinguished. Next to the first lightgreen it will appear of a deep-green, and in a few minutes change into a sea-green; after which, in a few minutes more, it will alter into a watchet-blue; from that, in a little time more, it will be of a purplish-red; after which, lying an hour or two, supposing the sun still shining, it will be of a very deep purple-red, beyond which the sun can do no more. But then the last and most beautiful color, after washing in scalding water and soap, will, the matter being again put into the sun or wind to dry, be of a fair bright crimson, or near to the prince's color, which afterward, notwithstanding there is no use of any stiptic to bind the color, will continue the same, if well ordered, as I have found in handkerchiefs that have been washed more than forty times; only it will be somewhat allayed from what it was after the first washing."

The RED WHELK, Fusus antiquus, is of considerable size, and found on the coasts of the British Isles. Like many other shells, on being held to the ear, it produces a roaring sound, popularly supposed to be an echo from the sea.

"The tinted sea-shell borne away,

Far from the ocean's pebbly shore,
Still loves to hum the choral lay,

The whispering mermaids taught of yore."

This species is hence called Roaring Buckie in Scotland; in the Shetland cottages it is used as a lamp. Other species are the DOG WHELK, Nassa reticulata; AUGUR-SHELL, Terebra maculata, &c. Several small species of buccinum are found on our coasts.

The PURPLE, Purpura Persica, is also very destructive to mussel beds, and yields a dull purple dye. The P. lapillus, and some other species, are found on our shores.

THE DOLIUM GALEA.

Genus HARPA: Harpa.-This includes the HARP SHELL, H. ventricosa, abundant on the shores of the Mauritius and of the neighboring islands. For this and analogous species, there are fisheries in those regions, the animals being caught at night or near sun-rise, by nets attached to rakes.

Genus DOLIUM: Dolium.-This includes the Dolium galea, found in the Mediterranean, generally on reefs.

THE STROMBIDÆ.

The animals of this family, called Wing Shells, have the outer lip of their shell much ex

THE STROMB.

panded; the foot is narrow and ill-adapted for creeping: the proboscis is large and thick, and the eyes large, supported on long, stout footstalks, from the sides of which the short tentacles rise. The species feed principally on carrion, and for molluscous animals they are very active. They progress by a sort of leaping movement, turning their heavy shell from side to side.

The STROMB, Strombus pugilis, is found in the West Indies, the Red Sea, India, Mauritius, and various other seas. The FOUNTAIN SHELL, S. gigas, found in the West Indies, is one of the largest of living shell-fish, sometimes weighing four or five pounds. As it becomes old, the apex and spires are filled with solid shell. Immense quantities are annually exported from the Bahamas for the manufacture of cameos and for porcelain works. In 1850, three hundred thousand were brought to Liverpool alone.

The CONCH SHELLS, formerly much used in this country by farmers to call their workmen to their meals, are of this genus.

The SCORPION SHELL, Pteroceras lambis-found in India and China—is of this family. Ten living and a hundred fossil species are known.

THE TURRITELLIDÆ.

In these, which may be called Tower Shells, and which derive their name from the Latin, turris, a tower, the shell exhibits a great variety of form, sometimes being semi-globular and

sometimes elongated, and tapering gradually to the apex. The Turritella rosea has the shell elongate, conical, smooth, and of a rosy color: found in New Zealand. The T. terebra, is found

There are fifty living and one hundred and seventy fossil species

THE LITTORINIDÆ.

This includes the COMMON PERIWINKLE, Littorina littorea, found on the sea-shore in all parts

of the world. It is oviparous, and inhabits the lowest zones of sea-weed between tide-marks. The L. rudis frequents a higher region, where it is scarcely reached by the tide. The periwinkles are exceedingly small, but their tongue is two inches long. Immense numbers of them are devoured by birds of various kinds. Nearly allied to the periwinkle, are the STAIR-CASE SHELL, of the genus Solarium, the CARRIER SHELL, of the genus Phorus, and the LOOPING SNAIL, of the genus Truncatella.

To this tribe belongs the genus Scalaria, popularly called Wentle-Traps; the shell is mostly white and lustrous, turreted and many-whorled;

the animal has a proboscis-like mouth, tentacles close together, long, and pointed, and the eyes

near their outer bases. There are nearly one hundred species, mostly tropical, but some are found in the Mediterranean, in various parts of the Atlantic and Pacific. On our coast six or eight species are found; among them the S. subulata, an inch long, of a bluish-white, varying to livid brown.

Some of the Wentle-Trap shells are of great value. The ROYAL STAIR-CASE WENTLETRAP, S. pretiosa, found in the China and Indian seas, formerly sold for four hundred dollars; a fine specimen is even now worth twenty to thirty dollars. On account of its value, Lamarck gave this species the specific name of pretiosa, that is, valuable or precious.

THE TURBINIDÆ.

In this family, the name of which is derived from the Latin turbo, a whipping-top, in allusion to the shape of the species, the shell is more or less conical or pyramidal; the animal has a short muzzle; the tentacles are long and slender, with the eyes supported on short footstalks near their bases. The interior of the shells are generally pearly. These animals are all marine, feed on vegetable substances, and are very widely distributed.

Genus TURBO: Turbo.-Of this there are sixty living and three hundred and sixty fossil species. The TOP-SHELL, T. marmoratus, has a turbinated solid shell, with convex whorls. Found in tropical seas. Other species are the PHEASANT-SHELL OF AUS

TRALIA, Phasianella Australis; the NILE HOOP-SHELL, Trochus Niloticus; and the T. imperi

ers.

alis. The latter is found only at New Zealand, and here it is rare; the shell is very beautiful, the whorls rising in a depressed cone.

The MARINE TRUMPET or TRITON'S SHELL, Triton variegatus, is elegantly variegated with red and bay, the edge of the outer lip spotted with black. It is a native of the Asiatic West Indian seas.

The GREAT TRITON, T. Tritonis, is the conch blown by the Australian and Polynesian IslandThe genus Triton is placed with the family Muricida by some authors.

VOL. II.-65

THE NERITIDÆ.

This is a small family, the typical species of which, Nerites ustulata, are called Sea-Snails :

they have a thick and rather globose shell, and are mostly marine; those of the genus Neritina, however, inhabit fresh water. The POLISHED NERITA, Nerita polita, is distributed through nearly all tropical seas.

THE PALUDINIDÆ.

This family includes several genera, having somewhat globular shells, with a thick olive-green epidermis. The RIVERSNAIL, Paludina Listeri, has a turbinated shell, with round whorls. Found in the Caspian and Black Seas. The APPLE-SNAIL or IDOL-SHELL, Ampullaria globosa, has a globular shell and a large ventricose body

THE POLISHED NERITA.

whorl; found in the West Indies, South America, &c. The A. dubia is found in the Nile. Several species of this genus, brought from Egypt to Paris packed in bran, were found living, though they had been four months in making the passage.

THE NATICIDÆ.

In these the shell, which is globular, composed of five whorls, and has an entire aperture, is partially inclosed in the mantle. The Natica canrena, found in various seas, is blind; it frequents sandy and gravelly bottoms, ranging from low water to a depth of ninety fathoms.

THE IANTHINIDÆ.

These are carnivorous and oceanic, and possess shells almost exactly resembling those of the land-snail; they are without eyes, and secrete a sort of operculum, which operates as a float, bearing them about upon the water. They occur in vast numbers in the Atlantic, and are sometimes driven by storms upon the coasts of Great Britain; the same happens on our shores. In 1839, great numbers of them were washed upon the beaches of Nantucket.

THE CALYPTRÆIDÆ.

These, called Bonnet Limpets, have a limpet-like shell, which is usually somewhat spiral at the apex; they appear to pass a sedentary life, attached to stones and rocks. Of the widely distributed genus Calyptræa, of which the CUP-AND-SAUCER LIMPET, C. equestris, is the type, fifty species are known.

THE HALIOTIDÆ.

In these, which are called Ear-Shells, the animal has a short muzzle and two branchial plumes; the shell has a spiral conformation, and the perforations for the anal siphon are arranged in a row along the back of the shell. The TUBER