Fio. 67.— 

 Tabe of a 

 tube -worm 



NATURAL HISTORY. 



from deep water. Several of these are shown in the foreground of the 

 plate facing page I !. and there the reader can see the beautifully banded 

 tentacles which project from the mouths of the tubes. Among these 

 a larger conical structure is shown, which serves as a door 

 to the tube. Disturb the animal, and in go all the varie- 

 gated, feathery tentacles, this plug following them and closing 

 the aperture completely. Almost identical structures, though 

 on a -mailer scale, are found in the minute Sjrirorbis. 



These serpulid worms construct the tube in which they dwell 

 by a secretion of carbonate of lime. Others of the tube-worms 

 are regular masons, taking particle after particle of sand or 

 gravel, and building up their tube, using, instead of mortar, a 

 cemenl secreted by themselves. One of the most common of 

 these tubes is shown in Figure 67; others are formed of larger 

 particles. One of these species — a long and slender form — 

 lives on sandy shores, and builds long, straight tubes, which 

 extend downwards to the depth of several inches. Frequently 

 ,:,: the sand around these is washed away, leaving the tubes pro- 

 grains of jecting an inch or so above the surrounding surface, so that they 

 present the appearance of stubble on a newly mown field. This 

 form is known as Clymenella. 



Though protected from sight by their tubes, these tube-worms embrace 



the mosl beautifully colored examples of all the great group of worms. 



There is not a color or a shade of color in the rainbow which cannot be 



tlleled among them, though most are ornamented with the more deli- 



ahades rather than the more vivid colors. Some are one uniform color, 



while others are banded or spotted in the most agreeable manner. In the 



tropics some of these tube-worms live closely associated with the corals, 



and then their hues agree with the colors of the polyps around them. If 



these are green or purple, the worms are the same. This seems to be a 



bective resemblance, for no fish, however fond he might be of a diet 



of worms, would care to attack a coral. 



'1 here are many forms usually regarded as worms the exact position of 

 which is very doubtful, but which need a moment's attention. First comes 

 a curious parasite, known as Jf^-ostoma, which lives upon the feather-star 

 Comatula) described on a preceding page. In general appearance it con- 

 forms but little to our conception of a worm, for it is oval and flat, shows 

 no traces of joints, and is provided with pincers to hold it in place upon 

 host. 



Phoronis is the euphonious name applied to a second of these forms, 



