Sir Wyville Thompson observed the _Pyrosomæ_ off the Cape Verde Islands, and refers to the “blaze of phosphorescence and train of intense brightness that followed the ship;” and, while he did not experiment with the animals in his cabin, as did Bibra, he says, “It was an easy matter to read the smallest print, sitting at the after port in my cabin; and the bows shed on either side rapidly widening spaces of radiance, so vivid as to throw the sails and rigging into distinct lights and shadows. The first night or two after leaving San Iago, the phosphorescence seemed chiefly due to large _Pyrosomæ_, of which we took many specimens in the tow-net, and which glowed in the water with a white light like that from molten iron.” Not the least wonderful feature of this animal is the variety of tints; white, green, various shades of deep red, orange green, and azure blue having been ascribed to it by different observers,--a fact that must stamp it as the most wonderful of all light-givers, a veritable living diamond. One of the most remarkable exhibitions of phosphorescence was observed in January, 1880, by Commander R. E. Harris of the steamship “Shahjehan,”--a display so unusual that I quote Capt. Harris’s letter in full; and, while he is inclined to consider the exhibition as possibly electric, it would seem that the luminous objects referred to were phosphorescent animals of some kind, and possibly may have had some connection with the phenomenon. “The most remarkable phenomenon,” says Capt. Harris, “that I have ever seen at sea was seen by myself and officers on the 5th instant, between Oyster Reef and Pigeon Islands (Malabar coast). At ten P.M. we were steaming along very comfortably. There was a perfect calm, the water was without a ripple upon it, the sky was cloudless, and, there being no moon, the stars shone brightly. The atmosphere was beautifully clear, and the night was one of great quietude. At the above-named hour I went on deck, and at once observed a streak of white matter on the horizon bearing south-south-west. I then went on the bridge, and drew the third officer’s attention to it. In a few minutes it had assumed the shape of a segment of a circle, measuring about forty-five degrees in length, and several degrees in altitude about its centre. At this time it shone with a peculiar but beautiful milky whiteness, and resembled (only in a huge mass, and greater luminous intensity) the _nebulæ_ sometimes seen in the heavens. We were steaming to the southward; and, as the bank of light extended, one of its arms crossed our path. The whole thing appeared so foreign to any thing I had ever seen, and so wonderful, that I stopped the ship just on its outskirts, so that I might try to form a true and just conception of what it really was. By this time all the officers and engineers had assembled on deck to witness the scene, and were all equally