That there is nothing mythical in the matter can easily be made apparent to any person who chooses to visit the sea-shore. At such locality he need have no difficulty in recognising the Hermit-Crab, or meeting with numerous specimens for examination. Supposing such a one is at a rock-pool, and, moreover, that he knows by sight the Buckie (periwinkle), and Common Whelk, he will probably in such case be aware that the animals occupying these shells are snail-like in construction, and that their locomotion is consequently slow and formal. If, therefore, when peering into any pool he sees the Buckie, for instance, apparently change its nature, and instead of 'Dragging its slow length along,' scamper off suddenly, or roll over and over from the top of an eminence to the bottom, he may rest assured that the original inhabitant has departed, and that its place is occupied by a Lobster-Crab. The cause of his strange peculiarity I will briefly explain. In the true Lobster the tail forms a most valuable appendage. In the tail the principal muscular power of the animal is seated; and by means of it, too, the animal is enabled to spring to a considerable distance, and also to swim through the water at will. This important organ is well protected by a casing consisting of a 'series of calcareous rings, forming a hard and insensible chain armour.' In the Lobster-Crab there is no such arrangement. 'The abdominal segment of this singular animal, instead of possessing the same crustaceous covering as the rest of his body and claws, is quite soft, _and merely enveloped in a thin skin_. To protect this delicate member from the attacks of his voracious companions, the poor Pagurus is compelled to hunt about for some Univalve, such as a Whelk or Trochus, and having found this, he drops his tail within the aperture and hooks it firmly to the columella of the shell. Why Providence has doomed the poor Hermits to descend to such physical hypocrisy, and clothe themselves in the left-off garments of other animals, it is not easy to conjecture. No doubt, besides the defence of their otherwise unprotected bodies, he has some other object of importance in view. Perhaps they may accelerate the decomposition of the shells they inhabit, and cause them sooner to give way to the action of the atmosphere; and as all exuviæ may be termed nuisances and deformities, giving to these deserted mansions an appearance of renewed life and locomotion, removes them in some sort from the catalogue of blemishes.'