Like the Lampreys, these Sea Eels make excellent food, and are often raised in ponds and carefully fed to give their flesh a delicate flavor. SAND EELS. The Sand Eel is an easily frightened little fellow who buries himself in the sand. He is quite handsome, being silvery-blue—brighter on the lower parts than on the upper, with the radiating fins first white and then blue in color. This Eel is seldom seen swimming about. It hollows out a burrow for itself in the sand to the depth of fifteen or twenty inches, where it hunts out worms on which it feeds, while it shelters itself from the jaws of the hungry Fishes which eagerly hunt for its delicate flesh. COMMON EELS. The plain, snake-like Eel classed under the name of Anguilla is found in European rivers, and in various parts of North America. Although it is sometimes eaten it is not considered especially good for food; it does not often measure much over two feet in length, and is covered with a soft, slimy skin, and sometimes with tiny scales almost too small to be seen. CONGER EELS. The Conger Eel of the United States which belongs to this family is often five feet or more in length, while the Conger Eel of Europe is very large, as thick as a man’s leg, and sometimes ten feet long. THE FAMILY OF RAIAS, OR FLAT-FISH. All the curious Fish of this family—which forms the second group of the Cartilaginous Fishes—are broad, and swim flat on the water, and they are distinguished by the spines or prickles which the different species have on various parts of their body, or on the tail. It is by these spines that the different members of this family are distinguished from each other. The Skate has the middle of the back rough, and a single row of spines on the tail. The Sharp-nosed Ray has ten spines that are situated towards the middle of the back. The Rough Ray has its spines spread over the whole back. The Fire-flare has but one spine but that is a terrible one. This dangerous weapon is placed on the tail, about four inches from the body, and is about five inches long. It is of flinty hardness; the sides are thin, sharp-pointed, and closely and sharply bearded the whole way. The White Ray, the Lump-fish and the Torpedo or Cramp-fish are the most important of this family, and these curious specimens are worthy of special description. THE WHITE RAY. [Illustration: WHITE RAY.]