750 THE LIVING ANIMALS OF THE WORLD 



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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 

 are 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-URCHIN.s 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, 

 the shell is oval and bilaterally symmetrical, though the dominant number of five still holds 

 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, orTrepang — 

 represent the only group which possesses a 

 substantial market-value. Its typical members 

 present an elongate worm-like contour, but pro- 

 gress 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 

 b^che-de-mer, are all inhabitants of tropical waters, 

 the North-eastern Australian coast and the Malay 

 seas yielding the most highly prized forms. The 

 Queensland Great Barrier Reef, consisting of a 

 series of coral-reefs extending for upwards of I.OOO 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 the}' 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 

 in aspect, and should rattle like dry walnuts when bagged up for exportation. From £i,0 to 

 £\'^o per ton are the prices that the better qualities of bechc-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 b^che- 



Phott h IV. Savtlh-Kint, T.Z.sr^ IMilfird-on-Sea 



A YOUNG BRITTLE STAR-FISH 

 (MUCH MAGNIFIED) 



The arms of the brittlc-itars are composed of loosely fittings 

 readily jractured joints 



