358 THE LIVING ANIMALS OF THE WORLD 



iwi/r..r,i.,,. In 



IT. SmOlfftmt. r 2 8.1 



SEA-WORMS. OR NEREIDS 



Tluir immmmerai>le "false /tit" impart ta tktm a centipede-like aspect 



most brilliant prismatic 

 tints. 



The T t r. 1 -n\\ BLLING 

 \\'di<MS arc note-worthy for 

 the elegant anil often beau- 

 tifully coloured flower-like 

 gill-tuft with which the head 

 is crowned. Its separate 

 filaments are clothed with 

 vibrating hairs, which en-ate 

 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 modifu-d as to constitute 

 a stopper-like organ, \\hcre- 

 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 distance* in every direction 

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

 The LEKCHKS differ essentially from the Bristle-worms in the absence of bristle* 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- ^^M 

 WORMS, LIVER-FLUKES, and 

 others. Among the free-living 

 non-parasitic members of this 

 group, the so-called INDIA- 

 RfHHER-WORM is remarkable 

 forthe extraordinary elasticity 

 of its tissue*. Black in hue, 

 it lives among rocks and - 

 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 f< < t 

 or more, and " playing" the 

 captured victim like a living ^^ 



<-la*tic fishing-line until it- sr \-MICE 



struggles are i-xhau-: ,. ,,. ilh ,.. , 



