Twelve species of the Trigula or Gurnards are known. The commonest species are the Grey Gurnard—a silvery grey Fish, clouded with brown, and speckled with black. This is found in British seas. The Red Gurnard is commonly found in the Mediterranean. This is a fine, bright red-rose color, paler beneath and more vivid about the fins. The Perlon or Sapharine Gurnard is a large species, handsomely marked with green and blue hues.
The Flying Gurnard is much like the other Flying-fishes in the formation of the front fins into wings, and in the manner of their flight, but their appearance is very different because of their queer armored head and the large eyes, as well as the brilliant markings peculiar to the Gurnard family.
[Illustration: SWORD FISH SPEARING HIS PREY.]
The Sword-fish, so called from the upper jaw being elongated into a formidable spear or sword, was known to the ancients, and has borne this name which recalls its important characteristic, from very early times. And while the Saw-fish, which belongs to the group of Cartilaginous Fishes, and a species of Sword-whale, have also been known as Sword-fishes, this species—scientifically known as Xiphias gladius—is the real, and the original Sword-fish.
This Fish attains a great size, being found in the Mediterranean and Atlantic from five to six feet in length. Its body is covered with minute scales, the sword forming three-tenths of its length. On the back it bears a single long dorsal fin; the tail is keeled, the lower jaw is sharp, the mouth toothless, the upper part of the Fish bluish-black, merging into silver beneath.
It seems to have a natural desire to exercise towards and against all the arm with which nature has furnished it; it darts with the utmost fury upon the most formidable moving bodies; it attacks the Whale; and there are numerous and well authenticated instances of ships being perforated by the jaw of this powerful creature, while the toothed spear of the Saw-fish has been found fast in the body of a Whale which it has pierced.
In 1725, some carpenters having occasion to examine the bottom of a ship, which had just returned from the Tropical seas, found the lance of a Sword-fish buried deep in the timbers of the ship. They declared that, to drive a pointed bolt of iron of the same size and form to the same depth, would require eight or nine blows of a hammer weighing thirty pounds. From the position of the weapon it was evident that the Fish had followed the ship while under full sail; it had penetrated through the metal sheathing, and three inches and a half beyond, into the solid frame.