Page:The common shells of the sea-shore (IA commonshellsofse00wood 0).pdf/34

24 thicker, stronger, and slightly wrinkled, until it is merged into the tube, which is strongly wrinkled throughout the whole of its length. In the dried specimen the membrane is less conspicuous than is the case when the animal is living; and as it becomes dry it is apt to become very brittle and flake off in scales. It generally, however, retains its hold of the shell at the base of the tube, and may be seen tucked into the opening like a half-drawn-off glove.

The shell itself is white, and with age attains thickness, so that a full-grown specimen is very weighty in comparison with other species of the same size. The ordinary colour of the shell is pale brownish yellow; but, like many other boring species, it is liable to be stained by the substance in which it lies. Many specimens are quite black, having lain in the peculiarly offensive deposit which is found towards the mouth of most tidal rivers. Sometimes it is red, exactly of the colour of iron-rust; and in every instance the edges of the slight ridges which traverse its surface are sufficiently abraded by the very slight movements of the animal, to prevent their discoloration, and to show the real tint of the unstained shell.

In some places the animal is used for food, and is sold under the name of "Old Maid." Plentiful as it is, comparatively few are taken, because they lie so well concealed that none but experienced eyes can discover them. Small holes in the sand or mud are the only indications of their presence; and as there are innumerable marine animals which make little holes in the mud, to distinguish the breathing apertures of the Gaper-shell is not a very easy task. The shell is seldom found less than a foot from the surface, so that to procure a large number of specimens is rather a laborious business. In the northern parts of the world, however, there are several animals which know where to find the Gaper-shells, and which are able not only to detect them, but to dig them from their muddy holes. The arctic fox is a terrible de-