The Living Animals of the World, Volume II: Birds, Reptiles and Amphibians, Fishes, Jointed Animals, Molluscs, etc.

previously referred to. In some, while the sub-spheroidal form of the case, or test, is still retained, the external- spiny armature is greatly varied. In one series these spines are exceedingly long, slender, and of needle-like contour and sharpness. In others, while long, they axe abnormally thick and cylindrical, somewhat resembling slate-pencils, for which they are sometimes used as a substitute; or they may be club-shaped, branched, or reduced to flattened plates. In other forms the shell itself is conspicuously modified. With some known as BISCUIT- or CAKE-URCHINS it is flattened out to the resemblance of a cake or biscuit, the spines being minute and inconspicuous. In another group, distinguished as HEART-URCHINS, still holdsthe shell is oval and bilaterally symmetrical, though the dominant number of five good with regard to the building up of its structural details. One of the most interesting is the LEATHER-URCHIN, so called on account of the flexible and loosely jointed character of its shell, the way being paved by such a form to the normally soft- and flexible-skinned sea-cucumbers. Sea-urchins are to a great extent vegetable-feeders, and the larger species are appreciated as an article of food in many countries, the ovaries, or roe, with which at certain periods the shell is mostly filled, forming the edible portion. The SEA-CUCUMBERS better known in the commercial world as Beche-de-mer, or Trepang represent the only group which possesses a substantial market-value. Its typical members present an elongate worm-like contour, but progress by means of extensile tube-feet, after the manner of the Urchins and Star-fishes, and have their dental, nervous, and muscular systems, fashioned on the same five-sectioned basis. The mouth, which is situated at one extremity of the body, is surrounded by a series of ten or twenty delicately branched or mop-like tentacles, which can be protruded or retracted at the animal's will, and are used for seizing food. The skin of the typical sea-cucumber is more or less soft and flexible, and has embedded within its substance innumerable minute calcareous spinules. The commercially valuable sea-cucumbers, or

Photo by W. Saville-Kent, F.Z.S.] [Milford on-Sea. beche-de-mer, are all inhabitants of tropical waters, A BRITTLE STAR-FISH YOUNG (MUCH MAGNIFIED). the North-eastern Australian coast and the Malay The arms brittle-stars of the are composed of loosely fitting, readily fractured joints. seas yielding the most highly prized forms. The Queensland Great Barrier Reef, consisting of a series of coral-reefs extending for upwards of 1,000 miles at a little distance from the Australian mainland, represents one of the most productive areas for this marine delicacy, the bulk of which goes to the Chinese market. The fishery is prosecuted with the assistance mainly of the Queensland natives, who, either by diving or wading on the reefs at low tide, collect the creatures in vast quantities. On being brought to the curing-stations, the animals are emptied from the collecting-sacks into large caldrons, where they are allowed to stew in their own juice for about twenty minutes. Taken out of the caldrons, they are split open and eviscerated, dried for a short interval in the sun, and then placed in tiers on wire gratings in a smoke-house, where they remain for twenty-four hours. They should at this stage have shrunk up to about one quarter of their normally extended size, much resemble charred sausages for exportation. From 50 toin aspect, and should rattle like dry walnuts when bagged up 150 per ton are the prices that the better qualities of beche-de-mer realise when well cured and delivered at Chinese ports. The chief culinary use to which the cured sea-cucumbers are applied is that of the concoction of soup, the best quality prepared taking rank with that made from swallows' nests. At the hotels and clubs in the leading Australian cities beche-

Starfishes, Sea* urchins, etc. 751

de-mer soup is held in high favour, and its more extensive introduction on the menu-cards of Western civilisation may be only a question of time.

Many species of sea-cucumbers inhabit British seas, but none possess that density of tissue which is essential for their economic conservation; the majority, moreover, are of comparatively small size, some few inches long only when fully extended, whereas the commercially valuable tropical ones may measure as much as from 2 to 3 feet. The mode of feeding of sea-cucumbers is somewhat interesting; the smaller species, with much-branching tentacles, generally affix themselves by their tube-feet to some object, and, extending their tentacles in all directions, utilise them, like those of a sea-anemone, for seizing any minute and suitable prey which may strike against them. The microscopic organisms on which they chiefly feed abound in the waters they inhabit, and one after the other, the branched tentacles having effected a capture, are gathered together and tucked bodily into the creature's central mouth and apparently half-way down its throat. The larger coral-frequenting species are provided mostly with mop-shaped tentacles. They crawl about leisurely in search of their food, mopping over the ground, and gathering up in their tentacles the minute shells and other organisms on which they subsist, which are col- riioto by W. Saville-Kent, F.Z.S.] [Milfm-d-on-Sea. lectively thrust with an indrawn tentacle into the A BRANCHING-ARMED BRITTLE-STAR. The specimen is attached to a brilliant scarlet sponge.

throat. In some of the lower forms the tube-feet have disappeared, the integument is thin and semi-transparent, and the worm-like animal crawls about by means of its skin-spinules, which take the form of anchors or grappling-hooks. In an opposite direction they may develop a supplementary covering of dermal plates and a more rigid integument, which indicate their nearer relationship with sea-urchins. The majority of sea-urchins and starfishes pass through a series of interesting metamorphoses before arriving at the adult state. The larval phases in these instances are free-swimming organisms, having arm-like processes, strengthened by calcareous rods that have been likened in contour to a clock- 1'koto by W. Saville-Kent,!'. [Milford-on-Sca. stand. A small spherical central area, like a

SEA-CUCUMBERS, SOME WITH EXTENDED 2lock in its case, representing the stomach of TENTACLES. the larva, develops spicules around it, and & West Australian species whose colours are bright pink and yellow. becomes the body of the urchin, the other

of the World752 The Living Animals

outlying portions becoming gradually absorbed. Some of the brittle-stars and sea-cucumbers bring forth their young in the adult form, nursing them from the egg in special breeding-chambers. The capacity of a star-fish to renew its lost arms is commonly manifested. A single detached arm, moreover, in such five- a type as the common fingered species, can reproduce its body and the remaining four arms. Fishermen, who are in the habit of tearing up starfishes and throwing them back into the water, under the impression that they are thus effectually incapacitating them

Photo by W. Saville-Kent, F.Z.S.] [Milj'ord-on-Sea. from further injury to their SEA-CUCUMBER, OR BECHE-DE-MER. oyster-beds, commit an error, These animals are collected in vast quantities on the Australian Great Barrier Reef, smoked, and such mutilation tending to the sent to the Chinese market. multiplication of their numbers. is richly endowed. Allusion In the matter of colour-ornamentation the Star-fish group to the brilliant crimson and pink-and-white tints of the British sun star-fish has been already made. As with most animal groups, however, it is amid their tropical representatives coral-that the most striking colour-variations obtain. One form which is common among the reefs on the Queensland coast-line, and much resembles the common British " five-fingers " in size and shape, is brilliant ultramarine-blue. Another large pentagonal species, belonging to the group known as Cushion-stars, has a golden-brown ground, upon which are thickly scattered small beadlike tubercles of turquoise. A third form, not uncommon on the Tasmanian coast-line, which is nearly related to the Bird's-foot species, previously mentioned, is distinguished by tints which range through several shades of crimson to brilliant violet.

Not a few of the starfishes are notable for their eminent phosphorescent properties. The group of the Snake-armed and Brittle-stars are more especially distinguished in this respect. Photo by W. Saville-Kent, F Z.S.} [Milford-on-Sea. Many of these species PRICKLY SEA-CUCUMBER. OCCUr in Such numbers in This SP60'63 of bSche-de-mer commands a high price in China, and makes delicious coup.

Star-fishes, Sea-urchins, etc. 753

Photo by W. Saville-Kent, F.Z.S.] [Miljonl-on-Sca.

BLACK SEA-CUCUMBER.

This photograph was taken through the water in a coral-pool. A large clam-shell, with its expanded fringe of tentacles, is close beside the sea-cucuruber.

comparatively deep water that the dredge may be filled with a tangled mass of their writhing is brought aboard, and its contentssnake-armed bodies. Should it be night when the- dredge are emptied upon the deck, the spectacle presented as the star-fishes scramble in all directions, their bodies and arms aglow with pale green or blue phosphoric coruscations, is highly remarkable,

CHAPTER IV.

MOSS-ANIMALS.

of animals whose relationship with the sub-divisions previously and A LITTLE group ./~V hereafter described cannot be very definitely determined is that of the MOSS-ANIMALS, sometimes designated CORALLINES, or LACE-CORALS. All its members are of exceedingly minute size, and if living separately would be scarcely discernible to the unaided vision. They are, however, in the habit of forming stocks, or colonies, after the manner of corals, by a process of continual budding, and in this way build up social aggregations which may be of considerable dimensions. The majority are marine, and largely in evidence on almost every seashore in the form of the so-called SEA-MATS, consisting of masses of minute, light brown, horny cells, which take the form of seaweeds, or are spread in thin, lace-likf encrustations upon the surfaces of shells, stones, and the larger seaweeds. The living inhabitants of these cells are as transparent as glass, their most characteristic feature being the elegant shuttle-cock-shaped crown of tentacles which is thrust out or withdrawn at will from the aperture of each tiny tenement. The assistance of the microscope is requisite for the apprehension of these details, as also of the somewhat complex alimentary and other organs enclosed within the component cells. 95