HAMMER-HEAD SHARK.
The Thresher, Thrasher or Fox Shark is a cousin of the porbeagle. Its peculiar characteristic is its long tail. Both the Atlantic and Pacific contain these fish. A length of fifteen feet is often reached. It will not attack man, but preys on small fishes. Swimming suddenly into schools of these, it flaps its tail rapidly, killing and devouring them in large numbers. These sharks are often found in companies attacking large whales.
The Basking Shark derives its name from its habit of lying at the top of the water with its upper back above the water line. This is the largest shark found in the Atlantic. It reaches a length of over thirty feet. The oil which its liver yields is valued and it is hunted on this account. It will not attack man.
Dog-fish is the general name for sharks of the families Scyllidæ and Spinacidæ. Dog-fish are the smaller types of sharks. They are sometimes eaten by fishermen on the Orkney Islands, a group of islands off the northern coast of Scotland, where they are dried for winter use. Their rough skins are used for polishing wood and is called shagreen. The dog-fishes reach a length of three or four feet. They frequently carry off the fishermen's captures from the lines.
Skates and Rays.
These are flat-bodied elasmobranchii. Skate is the common name applied to any one of the numerous species of flat elasmobranchii whose large, broad fins give it a somewhat diamond-shaped form. The commonest and smallest skate of the Eastern coast of the United States is the "Tobacco Box." The "Barn Door" Skate sometimes reaches a length of four feet, and the great Pacific Coast Skate is sometimes six feet long.
The Sting Ray bears on its tail a toothed spine some eight inches long and capable of inflicting a painful wound. Its tail is long and slim. As a rule they are confined to warm seas, but at least one species extends throughout the Atlantic and Pacific.
The Devil-fish or Eagle Ray is a member of the family of Millstone Rays, so called because of their peculiar teeth, which are adapted to crush the shells of the mollusks on which they prey. The tail is long and slim. Some devil-fish occasionally measure from fifteen to eighteen feet across. Pearl and sponge divers greatly fear these ugly creatures.
The name devil-fish is also given to the Octopus and to the Goosefish or Angler.