Now these are the paddles with which the crab rows itself through the water, and it is called the “Fiddler Crab” because the movements which it makes with them are rather like those of a man who is playing the violin. You can easily keep it in an aquarium, and a very interesting little pet it makes. But you must remember that it is a very savage little animal, and will certainly do its best to kill any other creatures that you may put into the same vessel. Even if you put two fiddlers together they are almost sure to fight; and the one which wins the battle will kill and eat the one which loses it. When the Fiddler Crab is alive it is really a very handsome little creature, for its blackish shell is covered all over with soft, short down, looking rather like velvet, while its legs are striped with blue, and its claws are partly blue and partly scarlet. PLATE XXIII THE MASKED CRAB (1) The broad shelly shield which covers the back of a crab is called the “carapace,” and there are certain markings upon it which are rather like the features of a human face. But there is one crab in which these markings are so deep and strong that it looks just as if it were wearing a mask. So it is always known as the “Masked Crab.” It is found on the southern and western shores of England and Wales, and you may always know it if you meet with it, not only because of the face-like markings upon its back, but also because its carapace is a good deal longer than it is broad, whereas in other crabs it is nearly always broader than it is long. Besides this, the great claws are not really “great” at all, for they are very long indeed and very slender, with quite small nippers at the tips, while the greater feelers are quite as long as the claws. So altogether the masked crab is a very odd-looking crab indeed. But if you want to find it you will have to look for it very carefully, for it has an odd way of burying itself in the sand, and only leaving just its feelers and its eyes above the surface. PLATE XXIII THE THORNBACK CRAB (2) This is perhaps the very oddest of all our British crabs. In the first place, it looks much more like a big spider than a crab; for its body is very small, while its legs are very long and very slender. Indeed, the group of crabs to which it belongs is often called “spider crabs” in consequence. In the second place, its carapace is covered all over with rather long sharp spikes, which project in all directions, so that it strongly reminds one of a tipsy-cake! And, in the third place, the crab nearly always has a number of tufts of sea-weed or sponge growing upon its back.