The mergirl dropped the oyster-shell on which the letter was written from her hand, then with a gliding and almost snake-like motion swam out of the cavern. She designed to consult “Anna Bailey,” a vivacious but shrewd merwidow who knew life and who usually wore the blue coat, with gold braid and brass buttons, of a dead sea-captain. This she did, by the way, from motives of vanity, not delicacy, for the merpeople have never eaten from the Tree of Knowledge and are clean of mind as the sea in which they live is clean. Of course there are exceptions amongst them. “Lord Aberdeen,” for example, was a notorious libertine, with the morals of a porpoise. “Marry him,” said “Anna Bailey.” “You take my advice. He cannot live long. And afterwards you’ll be among the wealthiest in the sea and able to marry again where your heart suggests. There he is. Mark my words: he’s nearly run his course. Blessed if he hasn’t got a face like a dog-fish! But what does that matter? You needn’t look at him.” “Lord Aberdeen” rolled by in a huge conch shell drawn by two sharks. His wicked little eyes glittered and he waved a pearl-laden hand to “Star o’ Boston.” Hardly had he disappeared when “Theodore H. Jackson” came along, swimming thoughtfully. He was a god-like merman, mighty of size, with hair as crisp and emerald green as sea-endive, with a fine forehead, a straight nose and ruby eyes, of a colour like to the red sea-anemones. “Come, ‘Star o’ Boston,’ my own little green-eyed love,” he said. “Leave talking with this worldly widow and follow me and take the air, for there is nothing like a whiff of the strange, pure fluid of the air-breathers at times of sorrow and anxiety.” He put his Titan arm round her, and they swam away to a little coral island in the Caribbean--one of those uprising islets not known of men and not marked in the charts of ships until some vessel has perchance found it in the dark, and gone down. Even so it was now; and as the merman and his maid approached along the dim-lit floor of the ocean to where the coral island swelled like a mountain through it, they saw, beside the great achievement of a million generations of coral insects, a lesser object lying unsightly, black and alone. “It is a new monster. Let us go speak with it,” said “Star o’ Boston,” who feared nothing but “Lord Aberdeen.” “Nay, golden-tail, ’tis a human wreck! Of such are the ships that sail the face of the sea. This is Fate, and we are the first to find it, save the fishes. Heaven grant there is bullion aboard, then all may yet be well.” [Illustration: “‘OLD TOM RUM,’ READ OUT ‘STAR O’ BOSTON’”] It will be news to the reader that the submarine currency depends on nautical mishaps. Their coinage is silver and gold. It explains a point which often puzzles quite well-informed people. Why do the Marine Treasure Recovery Companies never recover anything but old cannons and similar rubbish? Because the merfolks take the money and use it for their own purposes.