THE SHELLI-BINDER. 529 
To give the Sabella a variety of building materials, and to note which it accepts, is always 
an interesting amusement; for the worm is very fastidious, not to say capricious, in its 
choice, and always likes to have a stock of materials from which it may make its selection. 
While wandering along sandy coasts, we frequently come across some moderately large 
tubes projecting from the sand, and rather conspicuous in the little puddles left by the 
receding tide. Round their mouth is usually a set of forked filaments which, like the tube 
itself, are composed of fragments of sand agglutinated together. The substance of this tube 
is very soft, but very tough, and will endure a tolerably hard pull without breaking. If 
the inhabitant of these tubes be sought, it will not be found without much labor, for the 
TEREBELLA retreats to the farther extremity at the least indication of danger; and as the 
tube is 2 foot or more in length, and is always conducted under stones or among rocks, it is 
not easily dislodged. 
As in the case of the Sabella, this annelid performs its architectural labors by means of its 
tentacles, which are most wonderfully constructed, so as to be capable of extension or retraction, 
and at the same time can seize or throw away a particle of sand at any part of the tentacle. 
The method of working is very well given by Mr. T. Rymer Jones:—‘‘If a specimen be 
dislodged from its tube, it swims by violent contortions in the water, after the manner of 
yarious marine annelids; the tentaculee and the branchie are compressed and contracted about 
the head, like a brush ; and as the animal is very soon exhausted by such unnatural exertions, 
it soon sinks to the bottom. Should a quantity of sand be now scattered from above, the 
tentaculee, speedily relaxing, extend themselves in all directions to gather it up, sweeping the 
vessel quite clean, so that in a very short time not a particle is left behind that is within their 
reach, the whole having been collected to be employed in the construction of a new artificial 
dwelling, adapted to shelter the naked body of the architect. 
“We will suppose a tube to have been partially constructed into the side of the aquarium, 
wherein a specimen is about to take up its permanent abode. During the earlier part of the 
day, the animal is found lurking in its interior, with only the extremities of the tentaculee 
protruding beyond the orifice, and so it will remain till towards noon. 
‘** But scarcely has the sun passed the meridian, than the creature begins to become restless ; 
and towards four or five it will be seen to have risen upwards, the tentaculze extending with 
the approach of evening, until after sunset, when they are in full activity. They are now 
spread out from the orifice of the tube like so many slender cords—each seizes on one or more 
grains of sand, and drags its burden to the summit of the tube, there to be employed according 
to the service required. Should any of the tentacule slip their hold, the same organs are 
again employed to search eagerly for the lost particle of sand, which is again seized and 
dragged towards its destination. 
‘Such operations are protracted during several hours, though so gradually as to be 
apparently of little effect. Nevertheless, on resuming inspection next morning, a surprising 
elongation of the tube will be discovered ; or, perhaps, instead of a simple accession to its 
walls, the orifice will be surrounded by forking threads of sandy particles agglutinated 
together.” 
There are many species of Terebella. They have, to a considerable extent, the power of 
reproducing lost portions of the body; and it has been found that even the whole mass of 
plumy tentacles can be removed without much injury to the Terebella, which retreats to its 
tube, and after a while reproduces the whole of the missing organs. 
The SHELL-BINDER is very plentiful on some coasts, especially those where the shells of 
various mollusks are found in profusion. The tube of this species is built almost entirely 
of little fragments of shell, and is of very great length—so long, indeed, and going so deeply 
into the sand and among the stones, that to procure a perfect specimen is almost an impossi- 
bility, except by some rare good fortune. As this creature makes its dwelling about midway 
between high and low water mark, it may sometimes be procured by setting to work as soon 
as the tide has retreated, and, with crowbar, pick, and shovel, making the best use of the few 
hours that can be given to the task. I have never yet succeeded in extracting an entire tube. 
though I have often tried to do so. 
Vow. IIl.—67. 

