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and three-quarters of an inch in diameter, a good plan is to immerse them in methylated spirit for twenty-four hours or more, according to size. The alcohol removes the water from the tissues of the animals' bodies, and by destroying all putrifactive organisms renders them perfectly inodorous. Slightly warm the shells after removing from the spirit, when they will dry very rapidly, and may be placed in the cabinet almost immediately. It is surprising, too, how clean these shells become if left for some weeks in spirit. The green stains which are so common are entirely dissolved out, and the Nulliporites (vegetable concretions) are softened to such an extent that they can be scraped or picked off without difficulty.

Now for those shells of an inch and upwards in diameter, I am afraid the only commendable course is to boil them for a quarter of an hour or so, and then, with a sharp, curved skewer, using a twisting movement, carefully unscrew the animal out of the shell. You may manage to extract the body intact, and possibly you may not; a large portion of the tail or hinder end often being left behind in the spire of the shell. In that case the only plan is washing out vigorously every day with fresh water until the part begins to macerate, when it may be easily jerked out. With some species, boiling seems to injure the epidermis, and the colour suffers in consequence. It will be as well, under these circumstances, to save a few specimens and place them in a wooden box, perforated at the ends, so that, while blowflies, ants, and scavenger beetles may have free access to them, they are at the same time protected from the sun and rain. Wash them daily, but dry the shells every time water is used. Do not omit to keep the operculum for two or three specimens, as well as for your duplicates. When perfectly sweet and clean, the shells may be stuffed with cotton wool, and with a dab of liquid glue the operculum may be secured in its proper position. In order to remove barnacles, mussels, and other parasites, a piece of sharpened wood is the best thing to use, or a penknife; but the knife requires gentle manipulation, lest it damage the shell irretrievably. Some incrustations are best attacked with spirits of salts diluted with equal parts of water, but be sure to have a bowl of water at hand in which to dip the shell from time to time before corrosion proceeds too far. Then a rag, with a pinch of fine sand sprinkled on it, may be carefully rubbed over the shell, which should be examined every now and then to see how you are getting on; perhaps giving another touch of acid here and there to obstinate spots, but always with extreme caution. As this acid is corrosive in its action,