A quantity of blubber, from two to three and a half inches in thickness, and amounting sometimes to above half a ton, encompasses the whole body of the narwal, and affords a large proportion of very fine oil. In a fine fatty substance about the internal ears of the narwal are found multitudes of worms. They are about an inch in length, some shorter, very slender, and taper both ways, but are sharper at one end than at the other. They are transparent. The vertebral column of the narwal is about twelve feet in length. The cervical vertebræ are seven in number, the dorsal twelve, the lumbar and caudal thirty-five. The spinal marrow appears to run through the processes of all the vertebræ from the head to the fortieth, but does not penetrate the forty-first. The ribs are twelve on each side, six true and six false, and are small for the size of the animal. The principal food of the narwal are molluscous animals. I have found remains of sepiæ in several stomachs which I have examined. Narwals are quick, active, inoffensive animals, and swim with considerable velocity. They appear in numerous little herds of half a dozen or more together, each herd being most frequently composed of animals of the same sex. When harpooned, the narwal dives with almost the velocity of the mysticetus, but not to the same extent; on returning to the surface it is dispatched with a lance in a few minutes. Passing now from these tribes, a short space must be allotted to the description of the dolphins. The first is _Delphinus deductor_, defined by Dr. Traill, the ca’ing or leading whale. The following are its specific characters. Body thick, black; one short dorsal fin; pectoral fins long, narrow; head obtuse; upper jaw bent forward; teeth subconoid, sharp, and a little bent. This animal grows to the length of about twenty-four feet, and is about ten feet in circumference. The skin is smooth, resembling oiled-silk; the colour a white blueish black on the back, and generally whitish on the belly; the blubber is three or four inches thick. The head is short and round; the upper jaw projects a little over the lower. Externally it has a single spiracle. The full grown have generally twenty-two to twenty-four teeth in each jaw, and when the mouth is shut, the teeth lock between one another like the teeth of a trap. The tail is about five feet broad, the dorsal fin about fifteen inches high, cartilaginous, and immovable. This kind of dolphin sometimes appears in large herds off the Orkney, Shetland, and Feroe islands. The main body of the herd follows the leading whales, and from this property the animal is called in Shetland the ca’ing whale, and by Dr. Traill the deductor. Many herds of this animal have been driven on shore at different periods, and it is recorded that there were taken in two places in the year 1664 about a thousand; and in modern times extensive slaughters have taken place on the shores of the British and other northern islands.