Page:The common shells of the sea-shore (IA commonshellsofse00wood 0).pdf/40

30 called by the name of "Pandora," because the pearly box-like shell is fancifully thought to resemble the magic box in which Pandora kept her fatal gifts. As one end of this species forms a kind of beak, it is called the (Pandora rostrata).

The animal, too, is rather curious, as may be seen by reference to the illustration. The siphons are completely united to the end, but instead of the apertures opening in the same line, they diverge widely from each other. At the Cut on page 25, fig. 7, is seen the inside of the deep valve of this species, as well as the hinge of the flat valve. This sketch was taken in order to show the peculiar hinge, the shelly teeth, and the narrow and nearly straight elastic cartilage by which the valves are held open. Only two species of this genus are acknowledged as British; and the present species, although plentiful in the Channel Islands, is thought by some persons to have but a weak claim to the title of British.

We now come to another family, named Anatinidæe, or Lantern-shells, which are also burrowers, and generally live in the depths of sand or mud, although they are sometimes found in the cavities of rocks. One of the best-known British species is that which is shown at page 25, figs. 5 and 6, and which is called Thracia phaseolina. Perhaps we may name it the, the word phaseolina being formed from a Latin word signifying a bean.

This is a very common species, and found on most of our shores. Plentiful as it is, a really perfect specimen is not very often seen; for, in the first place, the shell is so fragile that it is easily crushed, and in the next place, it is a compound shell, having a supplementary piece which readily falls off, and is mostly detached before the specimen is discovered. If the reader will take a perfect shell and examine the hinge, he will see that just beneath the beak there is a small semilunar plate of shell, which partially overlaps the