Chapter 6

FEEDERS ON ANIMAL FOOD, (Zoophagi.)

Lamarck notices no less than 181 recent species of the Cone shell. The Marbled Cone figured below, is found in most of the Asiatic seas, and is not uncommon; it is of a dusky colour, and covered with angular white spots. The section of this shell points out in a remarkable manner the economy and providence of the Creator, so visible in all his works.

Voluta diadema.Conus marmoreus.Columbella mercatoria.

It will be seen on referring to the engraving, that the shell is much thicker in the outward part of its coat than in any other part; and this exceeding thickness is necessary for the protection of the soft body of its inhabitant. In the course of the growth of the animal the shell is enlarged, and that part that was external becomes internal, the last made portion of the shell forming the outer wall; if, therefore, the inner part of the shell retained its original thickness,its weight would become too great for its possessor. To guard against this inconvenience, and this useless waste of material, the creature possesses the power of absorbing so much of the substance of what now becomes the internal portion of its dwelling as is unnecessary for its present use, and of re-depositing the same on the outward wall of its mansion, where strength is most required[1].

The Cones, says Lamarck, are the most beautiful of all the univalve shells; the genus comprises the most valuable and the most remarkable specimens of this family, whether we look at the regularity of their form or the splendour of their colours. The beauty of many, but, above all, the extreme rarity of others, have given them a species of celebrity, and have caused them to be much sought after by collectors.

Oliva porphyria.

The Cones are found in the seas of hot climates, in from ten to twelve fathom water. The animal of the Cones has the head furnished with two tentaculæ, or horns, with the eyes on the summits; they only inhabit salt waters.

The genus Oliva is distinguished from the Cones by the groove or canal which separates the turns of their spire, and by the wrinkles on the columella. ThePorphyry Oliveis found in the South American Seas, on the Brazilian coast, and is the most beautiful and the largest species of the genus; it is of a flesh colour, with numerous lines of a reddish brown, forming angular figures of various forms, and covered with irregular-formed spots of a red or maroon colour. Its length is nearly four inches. There are nearly seventy species of this beautiful shell.

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; thesehaving 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.

TheCowrie shellis 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.

Lamarck says the observations of the habits of this creature tend to prove that, in addition to the power of completing its shell, as we have already noticed, it can, when its increased size has caused it to require a new habitation, desert its former shell and form a new one; from this it happens that the same individual can form successively many shells of different sizes, so that we find the same species both large and small.

When not in search of food, these animals are found buried in the sand, at some distance from the sea-shore, in temperate as well as in hot climates.

FamilyCOLUMELLARIA.

This family is distinguished, from the next in having the columella plaited, and a notch at its base. It does not include any shells with a plaited columella, the opening at the base being entirely smooth, that is, without a notch.

The Diadem Whorl Shell is a very beautiful specimen of its genus; it is marbled with white upon a yellow ground, but the markings become nearly obliterated by age: it is as much as seven inches in length, and is found in the Asiatic seas. The head of the animal of this shell has two pointed tentaculæ, with an eye at the outer base of each. Its mouth is a lengthened cylindrical and retractile tube, furnished with little hooked teeth; it has also a tube to conduct the water to the branchiæ, springing out obliquely behind the head.

The common Columbella is found in the Atlantic Ocean near the island of Gorée, and in the West India Islands; it is about three quarters of an inch in length. It is a sea-shell, and is found upon the coast; it possesses a very small oval operculum attached to its foot.

FamilyPURPURIFERA.

The notch at the base of the shells of this family is a kind of groove bent backwards and upwards, but not properly forming a canal, all the genera have an operculum. The name Purpurifera has been given to theseTrachelipodes, because some of the genera contain in a peculiar reservoir the colouring-matter with which the Romans, and other ancient nations, dyed their beautiful and well-known purple, which was so much in use before the discovery of cochineal.

The Harp shells are found in the Indian seas, and in great abundance also in the Red Sea. A very curious fact appears in the history of the animal of the Harp which deserves notice. It was observed a long time back by a German naturalist named Bon, but had since then been either forgotten or disbelieved: a recent traveller has confirmed its truth, although he notices it as a new discovery; it is as follows:—

Harpa musica.

The foot of the animal has the power of dividing itself into two portions; and one, namely, the hinder portion, can be separated from its body by the animal, when it finds itself suddenly in danger, andwishes to retire into the deepest recess of its shell; on this account it is without an operculum, which would evidently be useless, as it would be lost at the same time as the foot.

The Harps, says Lamarck, are very beautiful shells, and if they were less common, would, on account of their elegant forms and colours, become valuable in a collection. Some species, however, are still considered rare.

The Harps take their name from the fancied resemblance between the regularity and direction of the ribs on the shell, and the strings of a harp. The species are not numerous, not exceeding eight in number.

This species of Purpura is said to be that which was employed by the Romans in dyeing, but many others of the same family yield a purple colouring-matter. It is nearly three inches in length, and is found in the Atlantic Ocean and the Mediterranean.

The purple colour which this little Molluscous animal produces, was discovered by the inhabitants of the ancient city of Tyre, and was thence called the Tyrian purple. The circumstances which led to the discovery of it are very imperfectly known, but fiction has supplied the want of historical facts, and described its origin with sufficient minuteness of detail. According to one account, the merit of its discovery is due to a dog belonging to a certain Hercules. We are informed that when this dog was accompanying his master along the sea-shore, who was then following the nymph Tyros, the animal seized one of the Purpuræ lying on the sand, and breaking the shell with histeeth, his mouth soon became coloured with the purple juice. The nymph having observed the effect, immediately expressed a strong desire to have a dress dyed of the same beautiful colour; and her lover, no less anxious to gratify her wishes, at last succeeded in discovering a method of applying it to cloth.

This colour was so highly valued by the ancients, that it was either consecrated to the worship of the Deity, or conceived to be fit only for the garments of royalty.

Under the Mosaic dispensation, the stuffs for the service of the altar and the habits of the high-priest were enjoined to be of purple. The Babylonians devoted this colour to the dress of their idols, and most of the other nations of antiquity appear to have done the same thing. Pliny informs us that it was used by Romulus and the succeeding kings of Rome, as well as by the consuls and first magistrates under the republic. The Roman emperors at last appropriated it entirely to their own use, and denounced the punishment of death against those who should dare to wear it, although covered with another colour. This absurd and tyrannical restriction confined the dyeing of the Tyrian purple to a few individuals, and, in a short time, the knowledge of the process was entirely lost.

In the twelfth century, neither the creature that furnished the dye, nor the methods which the ancients employed to communicate to cloths the rich and beautiful purple which it afforded, were at all known; and on the revival of learning, it was even suspected by many, that the accounts which had come down to us respecting this celebrated colour were entirely fabulous.

According to Pliny, the Tyrians removed the finest colouring-matter outof the largest shells, in order to possess it in a more pure state, and to extract it more effectually, but obtained the colour from the smaller by grinding them in mills. He adds, that when the Purpuræ were caught, the receptacle which contained the dyeing-liquor was taken out and laid in salt for three days; and that after a sufficiency of the matter had been collected, it was boiled slowly in leaden vessels over a gentle fire, the workman scumming off from time to time the fleshy impurities. This process lasted ten days, after which the liquor was tried by dipping wool into it, and if the colour produced by it was defective, the boiling was renewed.

Other colouring-matters were employed sometimes to economize, and at other times to vary the effect of the liquors of the Purpuræ. Among these Pliny enumeratesFucus marinus, or Archil, and theAnchusa tinctoria, or Alkanet, both of which are still used as dyes. By these and other means, the purple colour was made to assume a variety of shades, some inclining more to the blue, and others to the crimson.

In modern times several attempts have been made to obtain this dye; but the discovery of cochineal has rendered it a matter of little import.

In the year 1683, Mr. William Cole, of Bristol, being at Minehead, was told of a person living at a seaport in Ireland, who had made considerable gain by marking with a delicate and durable crimson colour, fine linen that was sent to him for that purpose, and that this colour was made from some liquid substance taken from a shell-fish. Mr. Cole, being a lover of natural history, and having his curiosity thus excited, went in search of these shell-fish, and, after trying various kinds without success, he, at length, found considerable quantities of aspecies of buccinum on the sea-coasts of Somersetshire, and the opposite coasts of South Wales. After many ineffectual endeavours, he discovered the colouring-matter, placed in a white vein, lying transversely in a little furrow, or cleft, next to the head of the fish, “which,” says he, “must be digged out with the stiff point of a horse-hair pencil, made short and tapering, by reason of the viscous clamminess of the white liquor in the vein, that so by its stiffness it may drive in the matter into the fine linen or white silk intended to be marked.” Letters or marks, made in this way, with the white liquor in question, “will presently appear of a pleasant green colour, and, if placed in the sun, will change into the following colours,—that is, if in Winter, about noon, if in the Summer, an hour or two after sunrise, or so much before setting, (for in the heat of the day, in Summer, the colours will come so fast that the succession of each will scarce be distinguishable,) next to the first light green will appear a deep green, and in a few minutes this will change into a full sea-green, after which, in a few minutes more, it will alter into a watchet blue, and 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 the last and most beautiful colour, after washing in scalding water and soap, will (the matter being again exposed to the sun or the wind to dry,) be a much different colour from all those mentioned, that is, a fair bright crimson, or near to the prince’s colour, which afterwards, notwithstanding there is no styptic to bind the colour,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 alloyed from what it was after the first washing.”

Some years after this, Réaumur discovered great numbers of a species of buccinum, on the coast of Poitou, and the stones, round which they had collected, were covered with small oval masses, some of which were white, and others of a yellowish colour; and, having squeezed some of them on the sleeves of his shirt, in about half an hour he found it stained of a fine purple colour, which he was unable to discharge by washing. In repeating his experiment on his return home, he found it was necessary that the cloth should be exposed to the direct rays of the sun.

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.

FamilyALATA.

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 aconsiderable 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.

Pterocera scorpio.

FamilyCANALIFERA.

The shells belonging to this family agree with those of the last in having a canal at their base; but the lip to the right of the opening does not change its form through age.

TheTriton variegatum, or Variegated Sea-Trumpet, a large and beautiful shell, sometimes as much as two feet in length, is found chiefly in the torrid zones, near the Asiatic coast. The attendants on the sea-gods of pagan Rome are frequently represented with this shell applied to their mouth by way of a trumpet.

Already Triton, at his call, appearsAbove the waves; a Tyrian robe he wears,And in his hand a crooked trumpet bears.The sovereign bids him peaceful sounds inspire,And give the waves the signal to retire.His writhen shell he takes, whose narrow ventGrows by degrees into a large extent,Then gives it breath; the blast, with doubling sound,Runs the wide circuit of the world around.The sun first heard it, in his early east,And met the rattling echoes in the west;The waters, listening to the trumpet’s roar,Obey the summons, and forsake the shore.Dryden.

Dolium perdix.Triton variegatum.Pyrula caniculata.

This shell is found in the Icy Sea, and on the coast of Canada, and attains the length of seven inches. The animal of the Pyrula is at present unknown. There is a kind of keel or ridge along the edge of the whorls, which is obliterated in very old specimens. There are as many as eight-and-twenty species of this shell.

Turbo marmoratus.Pleurotoma babylonia.Trochus imperialis.

The Babylonian Split-Mouth is found in the East Indies and the Molucca Islands, and is about three inches and a quarter in length. It is said that the animal of this shell, when in motion, has its foot separated as it were from its body by a long thick footstalk, which arises from the centre of the mantle, which is at this time turned back over the shell. This separation of the foot has the effect of causing the creature to tumble over frequently, from the great weight it has to support.

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