358 THE LIVING ANIMALS OF THE WORLD 
[Milford on-Sea 
Photo by W. Saville-Kent, F Z S.] 
SEA-WORMS, OR NEREIDS 
Their innumerable ’''‘false feet^’’ i7npari to them a centifede-like aspect 
most brilliant prismatic 
tints. 
The Tube-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- ■ 
tides 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 INDIA- 
rubber-WORM is remarkable 
forthe extraordinary elasticity 
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 SEA-MICE 
struggles are exhausted® UPrms^ ^ulth rei^tarkablv irridescent hairs^ 'ivhich hurro'iv in the sand 
