A curious kind of prawn (by name Althea rubra), of fair size, is found under "the low-tide rocks" in the Channel Islands, which not only is of a deep crimson colour, but snaps his fingers at you--or rather one of his fingers--or claws--when you try to catch him, making a loud crack audible at ten yards distance. The common big prawn, if you see him in a large vessel of sea-water with the light shining through him, appears very brilliantly marked with coloured bands and spots--reddish-brown, blue, and yellow--which are displayed on a transparent, almost colourless surface. Of course, boiling turns him pale red. A common smaller species of prawn when boiled is often sold as "pink shrimps," and lately a deep-sea prawn--a third species--has come from the Norwegian coast into the London market. There are many kinds which are not abundant enough to become "marketable." Prawns are at once distinguished from the true "brown shrimp" by having the front end of the body drawn out into a sharp-toothed spine, which is absent in the shrimp. Besides the prawns (Palæmon and Pandalus), the shrimp (Crangon), and the common lobster (Homarus), you may see in the London fish shops the large spiny lobster (Palinurus) called "langouste" by the French, and apparently preferred by them as a table delicacy to the common lobster, although it has no claws. It used to be called "craw-fish" or "sea craw-fish" in London; why, I am unable to say. The name was certainly bad, as it leads to confusion with the cray-fish, the fresh-water lobster of British and all European rivers (there are many other kinds of fresh-water lobsters in other parts of the world, as well as fresh-water prawns and crabs), whose English name is a curious corruption of the French one, "écrevisse" (cray-vees, cray-fish). Another lobster of our markets is the little one known as the "Dublin prawn," which is common enough on the Scotch and Norwegian coasts, as well as that of Ireland. Naturalists distinguish it as Nephrops Norvegicus. The great edible crab completes the list of British marketable crustaceans, but in Paris I have eaten, as well as at Barcelona, a very large Mediterranean prawn, three times as big as our biggest Isle of Wight prawns, but by no means so good. It is called "Barcelona prawn" and "Langostino" ("Penæus" by naturalists). In Madrid I have seen in the fish shops and eaten yet another crustacean--a very curious one--namely, a long-stalked rock-barnacle of the kind known to naturalists as Pollicipes.