These deep-sea forms, especially of the genera _Asterias_ and _Ophiura_,[25] are remarkable for their brilliancy, even when taken from their native element. When the bottom off the coast of Ireland was dredged by the “Challenger,” an extraordinary number of luminous star-fishes were brought up from a depth of two-thirds of a mile. Several specimens are most noticeable for their brilliancy;[26] they appear as if burning internally with heat of great intensity. Even the mud about them was bespangled with luminous specks; and Sir Wyville Thompson says that in many instances every thing brought up in these waters was luminous. The light of one of the star-fishes was a brilliant green, and seemed to spring from the centre of the disk; flashing out now upon one arm, again upon another, or suddenly illumining the entire star in a brilliant aureola of phosphorescence. This resplendent creature is especially common, according to Sir Wyville Thompson, off the coast of Stornaway and Shetland; and the nets, when hauled in, were often overladen with masses of these gorgeous forms, which emitted a light of brilliant uranium green. Curiously enough, the young star-fishes exceeded the adults in the richness of their display. The gleams were not constant, but extremely erratic, appearing and re-appearing in a bewildering manner; and, according to the same naturalist, the most striking exhibitions were seen in very young ones. The star-fishes known as Ophiuroids are among the most abundant of deep-sea forms. On the “Challenger,” about several hundred species were brought up in the trawl from a depth of from half a mile to two and a half miles. In our own waters, two kinds[27] have been observed to emit a light of singular brilliancy. Even more beautiful than these, as regards their luminosity, are the Brisingas,[28] one of which is shown with its light in Plate VIII., Fig. 1. This animal has nineteen long, snake-like arms, branching from a small central circular body. Its color in the daylight is a rich orange red; but at night, when taken from the dredge, it displays a vivid phosphorescence. This attractive animal was first observed near Bergen, Norway, by Charles Abjördsen, who took a specimen in two hundred fathoms of water. Regarding it, he said, “it is a true _gloria maris_,” and gave it the name of _Brisinga_, one of the jewels of the Goddess Freya. The Brisingas have the faculty, common to many of their allies, of casting their arms when touched; so that it is extremely difficult to take them intact. In lifting an _Astrophyton_[29] from a branch of coral, we have had it drop into myriads of pieces; so that there was a mimic rain of arms upon the bottom. This we found could be avoided by making the transfer under water, and, when the “basket-fish” was safely in the jar, killing it by the introduction of alcohol.