756 THE LIVING ANIMALS OF THE WORLD 



Photo by W. SuM'Ue-Aeuf. F /. S.I [.ViV/on/t 



SEA-WORMS, OR NEREIDS 



Their innumerable "false feet*' impart to them a centipede-like aspect 



most brilliant prismatic 

 tints. 



The TUB E-DWELLING 

 WORMS are note-worthy for 

 the elegant and often beau- 

 tifully coloured flower-like 

 gill-tuft with which the head 

 is crowned. Its separate 

 filaments are clothed with 

 vibrating hairs, which create 

 currents bringing food-par- 

 ticles to the mouth In those 

 forms which build up a hard 

 calcareous dwelling-tube, one 

 of the gill-filaments is usually 

 so modified as to constitute 

 a stopper-like organ, where- 

 with the animal, on retreating 

 into its domicile, can effectu- 



ally bar out the ingress of in- 



truders. In some members of the group the gill-tufts are elegantly branched and supplemented 

 by long, simple, thread-like filaments, that are thrust out to long distances in every direction 

 both for food and the materials required for the further lengthening and enlargement of the tube. 



The LEECHES differ essentially from the Bristle-worms in the absence of bristles or 

 supplementary appendages, in the presence of an adhesive sucking-disk at the posterior and 

 sometimes also the anterior extremity, and on their well-known blood-sucking propensities. 

 While the MEDICINAL and so-called HORSE-LEECHES inhabit fresh water, some, more espe- 

 cially in tropical countries, infest the moist jungles and scrubs in vast numbers, and are among 

 the most actively aggressive pests with which the traveler has to contend. A few leeches also 

 inhabit the sea, preying upon the skate and other fishes. The bodies of these marine species 

 are cylindrical, with a sucker at each extremity, and roughly corrugated or warted. 



The FLAT- WORMS embrace a large number of intestinal and other parasitic species, includ- 

 ing TAPE- WORMS, THREAD- 

 WORMS, LIVER-FLUKES, and 

 others. Among the free-living 

 non-parasitic members of this 

 group, the so-called IXDIA- 

 RUBBER-WORM is remarkable 

 forthe extraordinaryelasticity 

 of its tissues. Black in hue, 

 it lives among rocks and sea- 

 weeds, and preys upon small 

 fishes and other organisms, 

 These being seized by the 

 suctorial mouth are unable to 

 effect their escape, the worm's 

 body being capable of stretch- 

 ing out to a length of 20 feet 

 or more, and " playing" the 

 captured victim like a living 

 elastic fishing-line until its 



are exhausted. 



SEA-MICE 



H>rM, ///& remarkably irriJescent 'iiiri, which burro-M in the sand 



