To remove the creature from its home is no easy matter as a rule. To pull it out by means of its legs or its antennæ would probably be to sever some portion of its body; but if you thrust the creature, shell and all, among the spreading tentacles of a large anemone, it will at once grasp the peril of the situation; and, if the shell has already been secured by the clinging petals of this dangerous marine flower, the hermit will speedily quit its home and endeavour to rush from the many snares in order to secure its freedom. Or, it not infrequently happens that the occupied shell is one that has withstood many a storm, but not without the loss of the apex of its cone. In this case the insertion of a very flexible fibre into the opening thus made will cause the hermit to leave its home in the possession of the enemy. Having, by some means or other, managed to drive the crab from its shell, we place it in a shallow rock pool, or in a vessel of sea water, and observe the chief features of its structure. The first thing that strikes one is the absence of a calcified skin on the extended abdomen, which is so soft that, remembering with what eagerness fishes will attack and devour crabs of all kinds, we can at once understand the necessity of such a home as the creature selects. Again, we observe the presence of appendages at the tip of the abdomen by means of which the crab is enabled to hold itself securely in the shell. Also, when we note the general form of the armoured portion of the body, and the position of the soft-skinned abdomen, we can see how well adapted the whole is to fit snugly into the spiral shell of a whelk or winkle. We also observe that one of the pincers is much larger than the other, and the value of such an arrangement may be estimated when we see the animal at home. The smaller claw, together with the other appendages used for walking or prehension, can be retracted within the shell, but the large claw, which constitutes a formidable weapon of attack and defence, is not only in such a position as to be ready for immediate use; but, lying as it does in front of the body, with other portions hidden more or less behind it, it serves the purpose of a shield when the animal retires.