528 THE SHORE SABELLA. 
into its tube the gills collapse and vanish, and the entrance of the tube is exactly closed by 
the conical stopper. 
The Serpula is a lovely inhabitant of the aquarium, but has an inconvenient habit of dying, 
sometimes coming out of the tube for that purpose, and sometimes retreating te its farthest 
recesses, and there pu- 
trefying, to the great 
damage of the aqua- 
rium. There are several 
kinds of Serpula, some 
of which are only 
attached by the lower 
part of the tube, and 
hold the rest of that 
wonderful structure up- 
right in the water; 
some, like the present 
species, intertwine their 
tubes very much like a 
handful of boiled mac- 
aroni; while others, 
such as the Serpula 
triquetra, form tubes 
which do not project at 
all, but are affixed to 
their supports through- 
out their entire length. 
This species makes a 
triangular tube. There SEKPULA.—Serpula contortuplicuta 
are many interesting 
circumstances connected with the habits and structure of these lovely worms, but our failing 
space will not admit of a longer description. 
We now come to another pretty tube-inhabiting annelid, mnieH is called Sabella, because 
it lives in the sand and forms its tube of that substance. Several species of Sabella are found 
on the European coasts, the most common of which is the SHORE SABELLA (Sadella alveolaria), 
a little creature seldom exceeding three-quarters of an inch in length. <As is the case with 
many of these worms, it has a thin tail-like appendage at the extremity of its body, which 
is doubled up within the tube. The head is furnished with a great number of little thread- 
like tentacles, which are very flexible, and under a good microscope are seen to have a groove 
running along the centre, and a double row of teeth along the edges, something like the snout 
of a saw-fish. 
This is a useful species to the naturalist on account of its plentiful occurrence, and readi- 
ness to work while in captivity. Ifa Sabella be watched while it is building up its curious 
tube, it will be seen to choose the particles of sand with the greatest care, selecting and seeming 
to balance them with the tentacles, and cementing each in its place with a glutinous secretion, 
which has the property of setting while under water. If the creature can be induced to build 
its case against the side of a glass vessel the possessor has cause to be gratified, for the creature 
does not waste material, and will often make the glass answer for one side of its tube, thereby 
permitting the observer to watch its entire economy. 
The skin of these worms is very tough. I remember once having to dissect the digestive 
organs for a lecture, and losing hour after hour in my endeavors to make a successful 
preparation. Just as the lecturer's servant came for the dissection, I had begun a fresh 
subject, and quite lost patience. So I gave the worm an angry tug with the forceps, when 
the whole skin of one side stripped off, leaving the digestive organs exposed as beautifully as 
if they had been carefully dissected. 












































































































































