While luminous fishes have been known for many years, the “Challenger” expedition brought many new forms to light, and the work accomplished by her officers may be said to have given a new impetus to the study of deep-sea forms. Off the north-west coast of Australia, the “Challenger’s” trawl captured the curious black fish _Echiostoma microdon_. The luminous spots were few in number, but so arranged as to be of the greatest service: thus two are found just below the eyes; above the maxillary there is a narrow, elongated one, with a smaller spot nearer the eye. _E. micripnus_, found in twenty-one hundred and fifty fathoms, has long, fringed barbels, and small, round luminous spots above the maxillary, resembling a rudimentary eye. Referring to this interesting torch-bearer,[43] Dr. Günther says, “The fishes of the family _Stomiatidæ_, to which this genus belongs, are armed with formidable teeth,--a certain indication of their predaceous habits and voracity. Their long body is covered with a smooth, scaleless skin, of an intensely black color. The vertical fins are close together, near the end of the tail, as in the pike, forming a powerful propeller, by a single stroke of which the fishes are enabled to dart with great rapidity to a considerable distance. A long filament is suspended below the chin; and, as it is frequently fringed at its extremity, it evidently serves as a lure for other fishes or _animalculæ_. Series of luminous, globular bodies run along the lower half of the body and tail; and some others of larger size occupy the side of the head, generally below the eye or behind the maxillary bone. This fish is sixteen inches in length. The end of the barbel, which was thickened, was flesh-color with a rose tint; there was also a rose tint on the dorsal and anal fins. The rest of the animal was of a dark color. The phosphorescent spots along the belly and radial and lateral line were red, as was also that below the eye.” It is not often that the light of these fishes is seen; but the late Professor Willemoes Suhm, while watching the great trawl come over the side upon a calm night, noticed a gleaming spot, and taking it out found it to be the little fish _Sternoptyx_. In referring to it he says, “It hung in the net like a golden star, as it came out of the darkness.”