“The second occasion of my meeting these creatures was in a high latitude, and during the winter season; the weather dark and gloomy, with light breezes from northnorth-east, in latitude 40° 30′ south, and 138° 3′ east longitude, at the western entrance to Bass’s Straits, and about eight o’clock P.M., when the ship’s wake was perceived to be luminous, while scintillations of the same light were abundant all around. To ascertain the cause, I threw the towing-net overboard, and in twenty minutes succeeded in capturing several _Pyrosomæ_, which gave out their usual pale-green light; and it was, no doubt, detached groups of these animals which occasioned the light in question. The beautiful light given out by these molluscans[A] soon ceased to be seen; but, by moving them about, it could be reproduced for some length of time after. The luminosity of the water gradually decreased during the night, and toward morning was no longer seen.” [A] When this account was written, the Tunicates were supposed to be mollusks.--NOTE BY THE AUTHOR. M. Peron, says Figuier, observed the beauties of the _Pyrosoma atlanticum_ on his voyage to the Isle of France. The wind was blowing with great violence, the night was dark, and the vessel was making rapid way, when what appeared to be a vast sheet of phosphorus presented itself, floating on the waves, and occupying a great space ahead of the ship. The vessel having passed through this fiery mass, it was discovered that the light was occasioned by animalcules swimming about in the sea, at various depths, round the ship. Those which were deepest in the water looked like red-hot balls, while those on the surface resembled cylinders of red-hot iron. Some of the latter were caught; they were found to vary in size from three to seven inches. All the exterior of the creatures bristled with long, thick tubercles, shining like so many diamonds; and these seemed to be the principal seat of their luminosity. Inside, also, there appeared to be a multitude of oblong, narrow glands, exhibiting a high degree of phosphoric power. The color of these animals, when in repose, is an opal yellow, mixed with green; but, on the slightest movement, the animal exhibits a spontaneous contractile power, and assumes a luminous brilliancy, passing through various shades of deep red, orange green, and azure blue. Professor Moseley captured a _Pyrosoma_ four feet long, ten inches in diameter, with walls an inch in thickness. It was placed upon the deck of the vessel, and, when the naturalist wrote his name upon the animal with his finger, it came out in letters of fire: each letter seeming to increase in size, until the entire name was lost in a blaze of light, that radiated rapidly and soon suffused the entire animal; presenting a marvellous spectacle, and showing, in a striking manner, how intimately the animals are connected. In Plate XVII. a _Pyrosoma_ of the largest size is shown in comparison with a native diver.