The greatest circumference of the whale is from thirty to forty feet. It is thickest a little behind the fins, or in the middle, between the anterior and posterior extremes of the animal, from whence it gradually tapers in a conical form towards the tail, and slightly towards the head. Its form is cylindrical, from the neck to within ten feet of the tail, beyond which it becomes somewhat quadrangular, the greatest ridge being upward, or on the back, and running backward nearly across the middle of the tail. The head has somewhat of a triangular shape. The under-part, the arched outline of which is given by the jaw-bones, is flat, and measures sixteen to twenty feet in length, and ten to twelve in breadth. The lips, extending fifteen or twenty feet in length, and five or six in height, and forming the cavity of the mouth, are attached to the under-jaw, and rise from the jaw-bones at an angle of about 80°, having the appearance, when viewed in front, of the letter U. The upper-jaw, including the “crown-bone,” or skull, is bent down at the extremity, so as to shut the front and upper parts of the cavity of the mouth, and is overlapped by the lips in a squamous manner at the sides. When the mouth is open, it presents a cavity as large as a room, and capable of containing a merchant-ship’s jolly-boat full of men, being six or eight feet wide, ten or twelve feet high in front, and fifteen or sixteen feet long. The fins, two in number, are placed between one-third and two-fifths of the length of the animal, from the snout, and about two feet behind the angle of the mouth. They are seven to nine feet in length, and four or five in breadth; and in the living animal are capable of considerable flexion. The whale has no dorsal fin. The tail, comprising in a single surface eighty or one hundred square feet, is a formidable instrument of motion or defence. Its length is only five or six feet, but its width is eighteen to twenty-four or twenty-six feet. Its position is horizontal. In its form it is flat and semi-lunar, indented in the middle, the two lobes somewhat pointed and turned a little backward. Its motions are rapid and universal; its strength immense.